I think If the mod was a Race07 Mod or Track, i.e. If you are not running the steam version (offline), like I do, it depends on what the mod is for. (i don't use steam, but it's something like C:\Programfiles\Steam\steamapps\>\GTR Evolution\ - you should be able to work it out )
If you are running the steam (online) version, then paste the gamedata and uidata folders into your main evo directory.
