A rich houseguest's charms make this the best top-down Vette ever By Frank Markus Photography by Scott Dahlquist Motor Trend, 2004-04-01 00:00:00 Something happened at the swinging Bowling Green bachelor pad of America's favorite sports car, the Corvette. A snooty rich aunt from Cadillac crashed and made herself comfy. But this visitor turned out to be more Auntie Mame than Auntie Em, and her high-class fun-loving ways rubbed off on our hero, who suddenly seems an all-new man. And the transformation is most evident when he's dressed in the top-down couture favored by his rich Auntie XLR. Don't get us wrong, as roadsters go--even $50,000 ones--the pre-XLR C5 Corvette was a stout piece of work, thanks to many patented structural design elements like bumper-to-bumper hydroformed frame rails (still the largest in the industry), a structural backbone tunnel, and a floorpan made of balsa wood and composite sandwich material. But when Madame XLR blew into town dressed to impress, she shared her fitness secrets with her new housemate. Both are better off because of the relationship. Stiffer, more compact bumper beams are more rigidly attached to the frame rails of the new car, and with shorter front and rear overhangs, they contribute more to chassis stiffness, especially near the suspension mounts. A new hydroformed lower-instrument-panel brace anchors the door pillars to the center console to help eliminate the dreaded cowl shake. And a thick aluminum panel replaces the steel sheet that's bolted to the bottom of the C5's central backbone tunnel. The aluminum door-pillar and windshield surround structure is redesigned to use more extrusions and fewer castings for improved dimensional accuracy and rigidity. In fact, this structure is so rigid that the C6 roadster passes federal roof-crush standards (which convertibles are not even required to meet) without the use of any pop-up or freestanding hoops or rollbars. Finally, a fiberglass tub forms the trunk and bonds the bodywork to the frame rails while segregating the trunk compartment from the passenger space to reduce body shake and dramatically reduce road noise. This also secures the trunk when the top is down and the doors locked--the C5's trunk compartment is always open to the cockpit. The design team launched a crusade to reduce cockpit noise that was just as vigorous as its effort to bolster structural rigidity. They added a startling 15 pounds of acoustic-damping material to further squelch tire, suspension, and road noise--amazing in a car for which light weight is valued as much as or more than high horsepower. (Don't worry, the engine lost 15 pounds to offset it, and indeed the base C6 roadster is expected to have dropped 50 pounds.) The new soft-top, available in black, gray, or beige, has been tailored and aerodynamically optimized to reduce wind noise. Its profile is rounder, its crossbows don't protrude as prominently, and the five-ply Twillfast fabric and rubber-membrane top is thicker to damp noise transmission. The side-window glass now powers down and up slightly when the door is opened and closed for a better seal, and extensive aero tuning has lowered the drag coefficient fractionally (from the C5 roadster's 0.31). In the interest of reducing weight and complexity, Corvettes have been traditionally fitted with a manually folding soft-top, and the C5's basic design carries over except that a single handle replaces the two header latches. When the rear of the top is raised, the tonneau panel hinges up from the back, the top drops into the trunk well, and the tonneau closes over it. Big News: An optional power-folding top is available for the first time on the Corvette convertible. It lowers in 18 seconds but otherwise looks and functions just like the manual top. Car Top Systems, the company that supplies the XLR's retractable hardtop, developed the mechanism that consumes no additional trunk space and adds just 15 pounds. Chevy expects 20 to 50 percent of buyers to pop for the power top, which should cost about $2000. The power top includes a movable partition to prevent luggage from straying into the top-stowage area. Folks operating the manual top are expected to notice foreign objects that could shatter their glass backlight. Lowering either top cuts trunk space from 10.4 to 5.1 cubic feet. Another new trick that appears here is a Bose AudioPilot sound system that switches to a unique noise-compensating and sound-equalizing algorithm when running with the top down. The radio's AM and FM antennas are now cleanly integrated into the rear-bumper fascia (the optional XM Satellite Radio adds a dorsal fin to the trunklid). Chief engineer Dave Hill hates window glare, so a swatch of black fabric covers the shapely body-color tonneau panel to prevent it from reflecting into the larger (by 18.5 percent) rear window. Chief engineer Dave Hill says that a small but vocal minority among the Corvette faithful has been agitating for a Z06 roadster. Such a beast is not likely to be approved on Mr. Hill's watch, but he promises the new Z51 performance package will give this roadster 75 percent of the 2004 Z06 coupe's performance on a track. For the C6, the Z51 kit expands from stiffer shocks, springs, and anti-roll bars to include new run-flat tires with an asymmetric tread design more like that of the Z06's non-run-flat tires, larger cross-drilled brake discs and high-performance pads, manual transmission gearing optimized for acceleration in the first three gears and for top speed in fifth, and, of course, the 400-horse LS2 engine. If all the above isn't sufficient evidence to convince you that this is the best Corvette roadster ever, just feast your eyes on the sculptural handiwork of Tom Peters's design team. Not everyone has been won over by the new car's black plastic grille or Ferrari Modena-esque headlights, but we think the C6's basic body design themes are striking, especially when viewing the open roadster from an above rear- three-quarter perspective. This angle showcases the boattail character lines, the strong rear-quarter shoulders, the engine-compartment exhaust scallop, and the Sting-Ray-esque front fender lines. Gorgeous. Let the drooling and dreaming begin, but hold those down-payment checks until this fall, when the roadster is expected to go on sale at a price near today's $51,535 base. Until then, we salute odd-couple roommates everywhere. And judging from the success of this pairing, we'd like to suggest the General consider ordering Caddy's sexy CTS-V to shack up in a Chevy plant, and make a real man out of that Impala SS.