2008 Mercedes-Benz SLR Mclaren Road Tests

Mercedes-Benz doesn't have a rear-mid-engine supercar in its model lineup as Ferrari and Lamborghini and Porsche do, so it has chosen to create, with lots of technical help and finally assembly by McLaren, in England, a sort of long-nose, short-deck front-mid-engine supercar. The engines are built in Germany by Mercedes-Benz's in-house high-performance shop, AMG, and shipped to England for installation in these very special bodies.

The roadster bodies are completely new, not cut-down versions of the SLR coupe bodies. They are made entirely of three-layer carbon fiber at McLaren's race shop. Carbon-fiber reinforced plastic, or CFRP, is about five times stronger than steel in crush (or crash) situations, at about half the weight. (It's also a lot more expensive.) The one-piece body is then fitted with a huge V-shaped aluminum beam structure on each side that attaches to the front of the firewall to carry the engine, transmission, front suspension and steering. The carbon fiber fenders and hood complete the body.

In front of all that, there is an elaborately constructed carbon fiber crash bar that can handle huge amounts of impact, after which its disposable cones crumble into dust as the impact progresses. At the rear, there is an all-aluminum independent suspension system that looks like it was ripped directly out of a racing car. No other car in the world is built quite like this one, and it is as beautiful underneath as it is brutish on the outside. The only major panels shared with the coupe are the scissor doors.

The 626-horsepower 5.5-liter supercharged V8 engine nestles under the long, long hood, breathing directly through the Mercedes-Benz star in the nose of the car, and exhausting through a compact, front-mounted exhaust system that exits through the bottom edges of the front fenders. This does three things. It works very well for emissions, keeping the catalytic converters hot. It helps the engine breathe better at higher rpm. It eliminates a lot of pipes and mufflers under the car, which has a flat bottom for aerodynamic purity. Oh, and four, it puts the sound of that V8 engine very close to the cockpit, where it can be appreciated. Read on to our Driving Impressions to see what we thought of all this.

There are a few options on the list, including 19-inch wheels in a turbine design; brake calipers painted in gold or red ($850); black carbon-fiber inserts in the interior panels ($1550); special Silver Arrow leather in 13 colors, with embossed SLR logos ($9,950); contrasting upholstery seams in 300 SL red, orion grey or black ($610); a two-tone steering wheel matching the second interior color ($610); floor mats with leather piping in the second interior color ($370); and provision for a mobile telephone with a universal interface. And that's about it. The standard navigation system is different from all other Mercedes-Benz systems, compact, but useful.

Part of the ordering process for any SLR is a fitting trip to Woking, England, where the cars are built, to select your paint (13 colors) and interior color, add your options, and be fitted for one of the four different bucket seat widths that are offered, from narrow to extra-wide. You also get a complete tour of the Mercedes-McLaren Formula One race shop and the rest of the $300 million McLaren Technologies facility, an ultramodern building with its own lake, built by one of the world's greatest architects, Norman Foster.

The main differentiator is the tight-fitting, tightly designed convertible top. Once the latch is released and the button pushed, a second push of the button will automatically stow and hide the top in a mere 10 seconds. Putting the top up is even easier than that. When the top is down, the decibels from the front fender-mounted exhaust pipes go way, way up, but that's part of the car's charm and part of what you're paying for in an exoticar like this one.

The rear bodywork behind the convertible top well contains an automatic air brake that functions like the ones used on Mercedes-Benz race cars of the 1950s, raising automatically to help slow the car and keep the rear end stable under hard braking. The rear underbody of the roadster has a built-in undertray to control airflow and add high-speed stability as well.

Don't look for a lot of fancy polished wood or chrome inside the SLR, because there isn't any. This is a very sporty interior, mostly black, with brushed finishes on most of the metallic pieces that don't flare back into your eyes in bright sunlight with the top down. Our silver test car had a black interior with a sort of terra cotta red accent trim, and it was all put together perfectly, with the accent on delivering necessary data to the driver as quickly and clearly as possible through two central instrument pods up high on the dash panel.

The way the engine and transmission mass have been centered and lowered in the chassis gives the SLR roadster a built-in willingness to turn left or right very quickly through the quick-ratio power steering system. The race-quality double-arm front and rear suspension systems combine with the extremely stiff body and chassis to give the SLR beautiful pinpoint steering and handling in open-road situations.

The electrohydraulic anti-lock braking system on this car is phenomenal. The 14.6-inch front and 14.2-inch rear discs are made of carbon fiber ceramic like racing brakes, and the system uses eight-piston calipers at the front and four-piston calipers at the rear. These brakes are powerful enough to generate 2000 horsepower of braking force, or 1.3g of braking deceleration, and the brakes are reported to last up to 180,000 miles before needing replacement. The brake pedal is very sensitive at first, but once you get used to using them, the brakes become an important tool in overall driving enjoyment. They work in concert with the air brake built into the body, which rises up at a 65-degree angle to increase braking at the rear and keep the car stable, and the brakes also have a hill-holder feature and a traffic-crawling feature that lets the driver use the accelerator pedal only in thick traffic to keep the car trudging along at speeds up to 36 mph. You can even have your brake calipers painted in a choice of silver, red or gold to match or contrast with the body paint.

In thick traffic and city driving, though, you have to be careful, because the long nose of the car is way, way out there in front of you, and you simply can't see it, so we'd recommend rear-first parking, because the rear end is easier to see.

NewCarTestDrive.com correspondent Jim McCraw test drove the SLR Roadster in Germany and filed this report from Konigstein.