The compact nature of the TT called for a transverse engine layout. This complicated things for the quattro, which needs to distribute torque between the front and rear axles. It was solved with a sophisticated and extremely fast-reacting electro-hydraulic system, the first such method of torque distribution in any Audi. The overall result is that torque levels between the front and rear wheels are controlled by a number of parameters, including wheel speeds, engine speed and torque.

To protect against side impacts on such a low-slung car, especially since there is no center roof post (B pillar), there high-strength aluminum side intrusion bars are part of the chassis. There's further support for the Coupe in a tubular steel reinforcement behind the doors. And in addition to the front airbags, there are head-and-thorax airbags mounted in the front seatbacks.

The Roadster was designed from the outset to take into account the lack of a roof, and it boasts a number of integral chassis-stiffening measures. These include a meaty dashboard mount and windshield frame, even thicker steel side sills, and strengthened A-pillars that contribute to excellent rollover protection.

The Roadster comes with either a manual-operated top or an optional power unit activated by a single button. A tonneau cover keeps the lines clean when the top is down, while an innovative, electrically powered glass windbreak, shaped to mimic the curves of the rollbars, slides up behind the passengers to minimize buffeting.

Pop the hood, and you might be like your goofy neighbor: Oh, this must be a rear-engined car, you could easily think. The four-cylinder mill looks less like an engine than a couple of black plastic suitcases crammed into a Karmann-Ghia trunk. This may be a car for drivers, but not for gearheads.