I have very skins and are very goods car exemple:Ferrari 360 modena,Ferrari F50,BWM NFSMW, etc....
1-Decoments/TrackMania/Skins/Vehicles/Carmommon
The Past:Vehicles and Carmommon you need create
2-go to Google Search:Crapark and download the car it you want
but not extract the file because if you extract the file the game does not identify,and then paste the file in the folder carmommon.
3-Open TrackMania Nations Forever and enjoy of you new cars
I have helped. My next post is about Download and install the tracks TrackMania Nations Forever