The Solstice comes standard with a 2.4-liter four-cylinder engine that produces 173 horsepower.It's adequate, though lacking in smoothness at high revs.The base model's windows are hand cranked, and air conditioning costs extra.

The Solstice GXP features a turbocharged four-cylinder that produces 260 horsepower and 260 pound-feet of torque.The GXP comes with more performance and safety hardware along with more convenience features.

For 2008, Pontiac has added some equipment to the base model, including a nicer stereo with XM Satellite Radio and an iPod interface.OnStar is standard, ABS and StabiliTrak are optional.The lined and insulated convertible top that was optional for 2007 comes standard on 2008 models.

2008 Solstice models equipped with the five-speed manual transmission get a new torque beam to isolate noise associated with abrupt torque transfer away from the passenger compartment.The system was originally developed specifically for the added power and torque of the GXP model, but was then extended to all manual transmission models late in the 2007 model year.

We preferred the GXP.The GXP delivers slightly better mileage according to the EPA, and the $5,700 price premium includes features most buyers would want as options on the base model, such as power windows, cruise control, ABS and electronic stability control.The net cost of the high-output engine and other performance-enhancing equipment is about $3,700, and we think it's worth every dime.The GXP engine uses the latest materials and control technology, and it is GM's first in North America with fuel-saving gasoline direct injection.

The Solstice would make a fine daily driver in many locales, though it has no place to put things.The lack of storage space and idiosyncrasies with the convertible top could get old.The lack of luggage space makes the Solstice a poor choice for long trips or airport runs.

Yet cars like this aren't purely about transportation.In many ways, the Solstice is a match for the Mazda MX-5 Miata.The Solstice is a traditional sports car with rear-wheel drive.Measured by objective performance benchmarks, the Solstice GXP can be compared with much more expensive, long-time roadster class stalwarts such as the Porsche Boxster and Audi TT.In practice, the Solstice doesn't offer the handling precision of these other sports cars, nor does it match their refinement, interior quality and general tightness.But we love the styling.

The Convenience Package ($395) adds cruise control, an enhanced Driver Information Center, and fog lamps.The Preferred Package ($625) includes power windows, door locks and body-colored power outside mirrors, along with remote keyless entry.

The Solstice GXP ($28,135) gets a turbocharged 2.0-liter four-cylinder engine generating 260 horsepower and 260 pound-feet of torque matched to a five-speed manual transmission.The GXP comes with more standard safety features, including ABS, GM's StabiliTrak skid-management system and a limited-slip differential.The GXP also gets power windows and mirrors, cruise control, audio controls on a leather-wrapped steering wheel, remote keyless entry, fog lamps and polished aluminum wheels.Tires are the same size as the base model's, but are Goodyear Eagle F1 high-performance units.

A five-speed automatic transmission ($925) and air conditioning ($960) are optional on both models.Leather upholstery is available for the Solstice base model ($690) and GXP ($525) and comes as part of the Premium Package, which upgrades the base model with a leather-wrapped steering wheel with audio controls.Audio upgrades include a high-watt Monsoon system with subwoofer ($395).There's also is an in-dash six-CD changer ($295), which retains MP3 capability and a separate input jack.Also available are metallic pedals ($115), a rear spoiler ($275), and carpeted floor mats ($80).The base model can be ordered with polished aluminum ($545) or chrome ($795) wheels.

The Solstice can be ordered with the limited-slip rear differential ($195) and a rock-hard Club Sport suspension ($1,095) for road racing.There's also an SCCA SSB Championship Edition package ($6,235) that combines nearly all available options except automatic transmission and the Club Sport suspension.Appropriately, Championship Edition models are available only in Victory Red.

The Solstice is equipped with the minimum passive safety features required by federal regulations, which means seat belts and dual front dual-stage airbags.Anti-lock brakes ($400) and StabiliTrak ($495) are optional on the base model.A tire pressure monitor has been added as standard equipment for 2008.

There's not a straight line, flat surface or right angle on the body of this car.Indeed, the only part formed by the traditional method of stamping a piece of sheet metal is the small panel behind the front wheel well.The rest are created with a process called hydroforming, which uses extreme water pressure to press sheet metal into a mold.Hydroforming increases rigidity without adding weight, which in turn results in a stiffer platform, the key to sharp handling, reduced vibration and a smooth ride.

The GXP can be distinguished by its black honeycomb grilles and small chin spoiler in front.It also features expanded brake-cooling ducts around the fog lamps, polished dual exhaust tips and standard polished aluminum wheels.

The convertible top is a triumph, stylistically.Granted, this car looks best with the top down, but even top-up the profile shows a nice aero look.The trick to the slick look is a couple of Ferrari Dino-like sail panels, or buttresses, book-ending the vertical rear window.These sails have a downside, however.

They add complexity to opening the trunk or raising and lowering the top, which tucks under the rear-hinged trunk lid covering the entire back part of the car.Click the remote or a button in the cockpit and three latches pop loose: one in the center for the trunk lid, the other two outboard beneath the roof sails.When it works correctly, the sails pop up and the trunk opens of its own volition.However, sometimes you have to push the sails up and lift the trunk lid.To close the trunk, you reverse the process, remembering to re-latch both sails.The entire process takes less than a minute, but it can be cumbersome just to drop a bag into the trunk.To be absolutely sure the trunk lid closes, with no warning light on in dash, you have to stand behind the car and put hands as close as possible to the far corners, then slam.Then you have to walk from side to side and make sure both roof sails are attached.When they're not properly planted in their attachments, they can look wrinkled and awkward.

The same process applies to opening and closing the top.There's a single release lever inside the car in the center of the windshield frame.Unlatch it to pop the trunk lid and you can heft the top back and drop it into the trunk from the driver's seat, but you still have to get out to close the trunk.It's not conducive to opening the roof at a stoplight if the urge strikes, or raising it quickly when the rain starts.

We found the seats felt comfortable after two hours at the wheel.The seats are supportive, with a one-piece back and integrated headrests.For people space, Solstice compares well with the Mazda MX-5 Miata, and its seats can accommodate fairly tall frames.The Premium Package leather in a Solstice GXP we drove was well tailored, with GXP embroidered on the seatbacks.

Most materials are generally good quality, particularly the leather, soft plastic and trim plastic.However, the hard plastic on the doors and dash looks and feels too much like hard plastic.

The three-spoke steering wheel could be thicker, but the optional leather-wrapped rim feels great.Cruise-control and audio buttons are embedded in the spokes.The dash design is simple, handsome and effective.The panel sweeps up from the center console, over the gauges and into the door panels.The gauges sit at the bottom of deep tubes, and while they're nicely shielded from reflection, they could be better aimed toward the driver's sight line.Four circular vents move plenty of air.

The three climate-control knobs are big and easy to find.The square stereo face plate stands out oddly from the nice flowing curves everywhere else in the car.The volume and tuning knobs are large and covered with the same soft, grippy material as those for the climate controls, making them easy to adjust.A row of buttons sits to the right of these gauges for hazard lights, traction electronics, fog lamps and dash lights, right where fingers stretch from the right hand when properly wrapped around the steering wheel.

The window switches are awkward to reach.With forearm flat on the driver's door arm rest, and the left hand resting at the door pull, the window switches sit somewhere under the wrist.It's difficult to slide the arm back to reach them (or the mirror adjustor), because the elbow is blocked by the seatback bolster.The driver must contort his or her left arm to try to get fingers on the switches.

Storage space is lacking in this car, and that might be the biggest single strike against the Solstice as a daily driver.The Solstice has a decent-sized glovebox, though smaller than average.It also has a bin behind the front seats on the rear bulkhead that will accommodate some CDs, but you can't get into it while driving and the plastic latch is easily broken.Likewise, the cupholders, which pull out from under the bin on the bulkhead, are as good as useless for the driver.Beyond the glove box and the bin, there are little pockets (more like rails) molded into the door jams.These will fit a pen or a CD stood on end, but you'll have to move the CD before you get out.There's really no room behind the seats.Accessories from the dealer or the aftermarket could come to the rescue, but otherwise there's no place to stash a phone, a pair of glasses, or a wallet.

The trunk is small.Doubling as storage for the convertible top, it provides 5.4 cubic feet of space with the top up, and just 2.1 cubic feet of space with the top down.Those numbers don't truly tell the tale, however.The elephant in the trunk is the gas tank, a big box that leaves barely enough room around the edges for small, soft-sided, duffel-bag-type luggage.While storage space in other small roadsters may not look significantly greater by the numbers, the practical, usable space in most is significantly better.

There's no room for a spare tire either.As with the MX-5, the Solstice comes with an emergency inflator strapped to the back wall of the trunk; in other words, air up that flat tire and continue.Or call a tow truck.

OnStar Turn-by-Turn Navigation is available on the Solstice.Turn-by-Turn allows subscribers to talk to a live advisor, who in turn sends complete step-by-step directions to the vehicle through the OnStar system.These audio directions automatically play through the vehicle's stereo as needed, triggered by OnStar's global positioning system capabilities and ultimately leading the Solstice to its destination.OnStar calculates the route and relays it to the car, rather than leaving the calculations to an onboard computer and displaying them as directions or a map.

The Solstice GXP offers some real performance from a turbocharged four-cylinder engine that produces 260 horsepower.It delivers an impressive 260 pound-feet of acceleration-producing torque as low as 2500 rpm.

With direct injection and other technologies, the more powerful GXP delivers better fuel economy than the base engine.Using the tougher 2008 tests, the GXP rates an EPA-estimated 19/28 mpg City/Highway compared with 19/25 mpg for the base Solstice.In both models, premium fuel is not required but recommended for maximum performance.

If you haven't tried a turbocharged engine in recent years, you'll be amazed at how evenly this one generates power.There is virtually no turbo lag (pause between flooring the gas pedal and surge from the engine).Indeed, the GXP rolls out its power in such a smooth, linear fashion that some might be waiting for an obvious peak or kick.

There really isn't one, but in fairly short order the driver comes to appreciate the usable amount of acceleration performance available over a wide range of engine speeds.Driving at a good clip is easier in the GXP, and acceleration is less dependant on gear selection.The GXP can rocket out of corners even if the driver selects a higher gear than he or she normally might.And in a straight line, it's quick.With an over-the-counter accelerometer, we timed a 0-60 mph run in less than six seconds, without resorting to an aggressive, high-rev start.The GXP is as quick as any car in its price range, and quicker than more expensive benchmarks.Moreover, the GXP's gear ratios require a shift into third just before 60, adding fractions of a second to the time.In other words, it's quicker than published 0-60 times suggest.

The shifter has nice, short throws, with no doubt as to which gear is sought or selected.Yet it takes quite a bit of effort to move between gears.This makes the gearchange feel a bit notchy, until the driver realizes that it's better to just shove the lever into the next slot rather than trying to finesse.

The shifter feel, and the plentiful torque combined with the hunkered-down driving position, contribute to a general feeling that the GXP is more muscular, more brutish, than the MX-5 and other small roadsters.

The GXP isn't tail happy, as you might expect in a light, high-powered, rear-wheel-drive car.Pushed hard, the Solstice GXP understeers.And w ith the traction electronics engaged, it resists any tendency for the rear wheels to slide.

The GXP responds promptly to inputs on the steering wheel, though with less enthusiasm than an MX-5.Near the center, the steering feels wooden.And the steering response isn't linear, meaning that it takes some practice to be sure how much the car will turn with a given input on the wheel.This gives the Solstice a cruiser feel that doesn't encourage hard driving the way an MX-5 does.

There are other identifiable traits in the GXP package that don't match up to class benchmarks.The brakes stop the car right now, with good pedal feel at first.But the harder and longer you use them, the more the pedal softens and its travel increases.In other words, hard driving can bring on brake fade.Also, the clutch engages abruptly, to the point that it's easy to stall the car during casual starts at low revs.

That said, the Solstice GXP makes a fine high-speed cruiser.It tracks straight and true at interstate speeds-plus, and the ride is not disruptively bouncy.With the now-standard premium acoustic headliner, the top is well insulated and conversation is easy.

NewCarTestDrive.com correspondent Tom Lankard filed this report from Northern California's Central Valley and Sierra Foothills; with Mitch McCullough reporting from Los Angeles.