they're all excellent cars but remember how fast a chipped S4 is running. The NSX was actually the 1st car that came to mind when I saw that you were paying cash for your S4 though. I test drove a '94 NSX from Birmingham imports last year and fell in love with it. 65k miles and the dealer was talking in the $35,000 range. Driving it was unlike anything I've ever driven, the acceleration was damn near blistering and it had a decent level of refinement as well. Handled like crazy and didn't do too bad with the potholes on 14 Mile either.

but the body style is over 10 years old and the new model will be released within the next few years. but still, add a body kit and some new rims and that car still looks tight. Plus they're relatively a solid sports car, I read a few articles talking about the car's longevity if maintained right. If I were you I'd keep the SVT as your daily driver and get that NSX for play laugh. Either that or you could save 10 grand and get a Supra with 400+ hp...