Take a look at this video of an Audi R8 with the V8 motor outfitted with a custom twin turbo package from Heffner Performance.  Using 93 octane and only 6 psi of boost, it put down 536HP to the wheels.

Take a look at this great video of a yellow 2005 Lamborghini Gallardo racing against a silver Audi RS6 Avant on an airstrip in Germany. The 2005 Gallardo is powered by a naturally aspirated 5.0 Liter V10 engine producing 500HP with the E-Gear transmission and weighs in a about 3400 pounds. [...]

The 2008 model Audi TT comes in a Hatchback Coupe and Roadster. This is almost a luxury sports car with the price tag of about 40K (+- few thousand base on what you want with the base).
The name TT means Tourist Trophy, and has been quite a success since its launch in 2000.
The specs is [...]