tracks:
C:\Program Files\Steam\SteamApps\**username**\race 07\GameData\Locations\
Car Mods:
read the readme.... but usually:
C:\Program Files\Steam\SteamApps\**username**\race 07\
as they install into a group of folders... so the downloaded zip/rar/7z file will contain a GameData folder with all the files in the right folders so you just need to extract to the main race folder...