Corvette ZR1 for X Motor Racing is available for downloading. New physics, sounds and materials.
https://mega.co.nz/#!Gl4SCTyZ!UcTlnrNnclwJC7C0ecLbN7r4mNZDCgEmjY6Z4h5Ivso
http://www.mediafire.com/download/z1lo8qsrs96h2q4/xmr_corvette_zr1.rar
Download the car, unpack, copy to XMR folder and enjoy it. It works with the full version.