Originally Posted by Mike-in-Orange

The Viper ACR may be a production vehicle, but it destroys a stock Viper. The 599XX is, just as Ferrari states, "derived from a production car" which means exactly that - they started with a production platform and modified it, just as Dodge did with the Viper ACR. Except that Ferrari took the derivation to an extreme with this car. Nonetheless, the original canvas was a very comfortable road car. And in a way, I'm more impressed that a car like this or the ACR are as capable as they are. The Radical was a clean sheet, build it for the track race car - the ACR and 599XX took an existing platform and modified it to achieve stunning performance. In a way, the Corvette ZR1 fits this concept, as does the Porsche 911 GT3, both taking the stock vehicle and modifying and adapting it to be something extra hardcore. Again, neither went as far as the ACR, and certainly nowhere near where Ferrari took the 599.