http://www.lespittet.com/jeux/need_for_speed/nfs_4/voitures/index.htmMaybe this link can help? It was posted on NFSCars earlier today, these are all NFS HS cars from 1999 and early 2000.
The problem is though, that there are no preview images, and most ZIPs have their readme.txt removed.
So if you suspect one of these files might be the RK car that you are looking for, the only way to find out, is to install it and look for the trademark right-hand driver with the red helmet...
(I also don't know if you're interested in NFS3 cars, but that site's got an even bigger collection of those)