If you were to dream up the ideal attributes for a sports car, they'd probably end up a lot like those of the 2010 Nissan 370Z. With the Z, you've got a proper two-seater with rear-wheel drive, 300-plus horsepower, seductive styling, petite dimensions, big wheels and a curb weight under 3,300 pounds. It's seductively priced, too, starting right around $30,000. Of course, like many transitions from dream to reality, the real-world Z isn't perfect. But this latest incarnation of Nissan's iconic sports car is indeed something to lust after.

The redesigned 370Z coupe was introduced just last year, wowing us with performance numbers that are on par with much more expensive vehicles. As a 2010 encore, Nissan is bringing out the 370Z roadster. Equipped with a conventional soft top, the Z roadster is impressively similar in character to the coupe. It comes with the same drivetrain, a high-revving 3.7-liter V6 that's paired to either a six-speed manual transmission or a seven-speed automatic. The roadster's curb weight is only about 200 more pounds than the coupe's, and its suspension tuning is very similar. As such, the roadster mostly retains the coupe's quick reflexes and powerful acceleration.

Yet just when you think that the 370Z has given you a permanent pass to sports-car nirvana, a couple of character flaws surface. The V6 lacks aural flair and, more important, has a high-rpm coarseness that substantially dulls the enjoyment a driver would normally get from a spirited run. The Z is also noisy, particularly the coupe with the bigger tires and wheels. These might seem like spurious complaints -- aren't all sports cars noisy? -- but a performance car deserves an invigorating engine note, and excessive tire roar makes long freeway trips laborious.

These two flaws are unfortunate, as the rest of the 370Z package is stellar. Overall, Nissan deserves a salute for keeping the Z torch burning brightly. Even so, the door has been left open to other possibilities, including the more refined BMW 1 Series, the capable Hyundai Genesis coupe, the related (and considerably more polished) Infiniti G37, the inexpensive Mazda Miata and America's triumvirate of reborn pony/muscle cars. But if your dreams are about an affordable high-performance sports car, getting a 370Z is the best way to make them come true.

The 2010 Nissan 370Z is offered as a two-seat coupe or a convertible soft-top roadster. The coupe is offered in base, Touring and Nismo trim levels, while the roadster comes in base and Touring only. Standard features for the base 370Z coupe include 18-inch alloy wheels, xenon headlights, heated side mirrors, cruise control, keyless ignition and entry, automatic climate control, an auto-dimming rearview mirror, a tilt steering wheel, an eight-way manual driver seat and a four-speaker stereo with a CD player and an auxiliary audio jack.

The 370Z Touring coupe adds leather and faux suede upholstery, power seat adjustments, heated seats, a rear cargo cover, Bluetooth and an upgraded Bose stereo with six speakers, two subwoofers, an in-dash six-CD/MP3 changer and satellite radio. The track-focused 370Z Nismo comes with special 19-inch wheels, high-performance tires, a limited-slip rear differential, stiffer suspension tuning, a more powerfully tuned V6, upgraded brakes, unique front and rear fascias, a larger rear wing and special Nismo interior trim details.

The 370Z roadster comes standard with a power-operated soft top but is otherwise equipped similarly to the coupe, though the Touring roadster also has heated and ventilated seats. Optional on both 370Z models is a Sport package that adds 19-inch wheels, a limited-slip rear differential, upgraded brakes, front and rear spoilers, and the SynchroRev Match feature for manual-equipped cars. Optional on the Touring is a Navigation package that includes a hard-drive-based navigation system, real-time traffic and weather updates, Zagat restaurant reviews, voice recognition, digital music storage (9.3GB), Bluetooth audio streaming and an iPod interface.

The 40th Anniversary package (late availability) includes a unique two-tone interior with red trim, 40th Anniversary seatback embroidery and exterior badging, a car cover, gray-finished wheels, red-painted brake calipers and an exclusive gray exterior paint color. It will be offered only on the 370Z Touring manual transmission model with the Sport package.

Regular Nissan 370Zs are powered by a 3.7-liter V6 good for 332 hp and 270 pound-feet of torque. A six-speed manual transmission is standard. When equipped with the Sport package, a manual 370Z also comes with the SynchroRev Match feature, which automatically matches engine rpm to wheel speed during downshifts to make clutch re-engagements super-smooth. A seven-speed automatic transmission is optional and includes steering-column shift paddles and rev-matched downshifts of its own.

The 370Z Nismo has a tuned version of the same engine that develops 350 hp and 276 lb-ft of torque. The six-speed manual with SynchroRev Match is the only transmission offered.

In performance testing, a 370Z coupe with the Sport package went from zero to 60 mph in an impressively quick 5.1 seconds; a roadster we tested did it in 5.5 seconds. EPA estimated fuel economy for the coupe checks in at 18 mpg city/26 mpg highway and 21 mpg combined with either transmission. Roadsters have an 18/25/21 mpg estimate with the automatic and 18/25/20 with the manual.

Standard safety equipment for the 2010 Nissan 370Z includes antilock brakes with brake assist, traction and stability control, front-seat side impact airbags, side curtain airbags (roof-mounted in the coupe and door-mounted in the roadster) and active head restraints. In Edmunds brake testing, a coupe with the Sport package's upgraded brakes stopped from 60 mph in a super-short 101 feet -- about the same as the outlandish Nissan GT-R supercar. A roadster with the Sport package took only 5 more feet to stop.

On the road, the 2010 Nissan 370Z provides unrelenting grip and razor-sharp control, yet it's also easy to drive; indeed, it generally makes you feel like a better driver than you are. The ride quality is European-like in its ability to be supple without mucking up the handling. However, the Sport package's 19-inch wheel-and-tire combo can get awfully noisy, especially on concrete highway slabs. Thankfully, the roadster fares a bit better in this regard than the hatchback coupe due to its enclosed trunk. The 370Z Nismo's ride quality is substantially stiffer, but the car's super-flat cornering attitude and tenacious grip make it a track-day star.

In any Z, the big V6 provides formidable thrust when you're hard on the throttle, yet it's also impressively tractable around town. Either transmission is a respectable choice. The manual shifter doesn't like to be rushed, but its hefty feel suits the overall solidity of the car. The automatic does a wonderful job of keeping the V6 on boil, and it provides quick blip-throttle downshifts in all modes. Disappointingly, though, the 370Z's V6 never sounds particularly special (even from the exhaust) and generates extraordinary vibration and harshness at high rpm.

The 370Z's cabin is notable for its unusually high-quality materials and solid construction. Touring models look even more high-class thanks to their leather upholstery and upgraded faux suede door inserts. The fully automatic top for this year's new roadster is lined and drops down beneath a body-color tonneau cover in about 20 seconds. Curiously, the Z doesn't have a telescoping steering wheel, but most drivers will find the driving position comfortable and sporty.

Neither version is going to haul around much stuff, though the equivalent of two or three duffel bags won't be a problem and the large structural brace that bisected the trunk in the old 350Z has thankfully been relocated. The coupe has 6.9 cubic feet of luggage space beneath its hatchback; the roadster's conventional trunk has 4.2. Rear visibility is a problem, as the thick rear roof pillars create large blind spots.