I have found these 2 mods on calluster.com, both still in early stages, but very good already. The Callusyer LeMans has most of the great Sport Prototypes of the 80's; 956, 962, Jag XJR, SauberC9, Mazda 787B, etc. All have different sounds, great tire and brake models( from historx I believe), and look fantastic tearing around LeMans. 230mph so far in the Jag.  http://league.calluster.com/downloads/file.php?id=437  

Also, the F1-75 Mod, which is an updated version of the F1 70s mod. Great physics and sounds. A blast to drift!   http://league.calluster.com/forum/viewtopic.php?f=133&t=1405