We watched the Stig race a 2009 BMW Z4 around the track on "Top Gear," but we didn't realize how truly good this car is until we did our own racing around Northern California in one. The model we had in for review was loaded with the twin turbo engine, making it the sDrive35i trim, twin-clutch gearbox, and M suspension, which has three modes. It's an expensive car, but as we crushed turn after turn, it seemed worth every penny. And that's not even going into the cabin tech, which BMW also liberally loaded into this car. The audio system alone is phenomenal, using 16 speakers to fill the small cabin. Everybody on the CNET Car Tech staff lusted after this car after spending time behind the wheel.