One of our favorite sports cars, the C63 AMG is a Mercedes-Benz C-class car that has gone through the company's AMG tuning division. The result: a taut car with a big engine that handles extremely well, but gets horrible gas mileage.
The standard C-class is a small sedan with a distinctly Mercedes-Benz look. The AMG division makes some body changes for the C63 AMG, swapping out the front air dam and hood, and adding a rear diffuser. The new hood has bulges which Mercedes-Benz calls Power Domes.
The standard C-class handles fairly well, so the AMG division did not need to change too many components. But tuning keeps the car flat in the turns, while traction control programming lets the rear end come out a bit in hard cornering, contributing to rotation.