Your best bet is to install Nascar Racing 2003 and then grab a
Car
Of
Tomorrow mod.
You can get the COT mod
HERE
And dont forget to tweak the game so you get high rez textures with your setup.
Pay particular attention to the TextureSetSize and make sure its correct for your video card, otherwise it wont look near as good as it should. (dont forget windows has a calculator if you dont have one handy

)
Tweaks are
HERE
And thats the Best Nascar Racing experience you can get since EA took the Nascar exclusive and have been cranking out crap with it ever since.
And there are a lot more mods for NR2003 out there, try reading the posts at the
Blackhole Motorsports Forums.