Top Gear Magazine had an article about the amazing Callaway C16 Speedster. They basically took a stock C6 Vette, stripped it down, and re-engineered it from the group up. Its close to the factory ZR-1 but faster due to improved aerodynamics.
Link
Apart from the featherlight magnesium and carbon-fibre rims, the StopTech/Callaway carbon ceramic brakes and the race-sorted Eibach suspension - all items you can buy and from the C16 á la carte menu - the really stand-out features, the bits that really make this $170,000 car special, are the C16 bodyshell and interior.
Link