A skin I made this evening, just for fun. Really simple one, but thought I could share it anyways 
Simply unpack in C:\ProgramFiles(x86)\Steam\SteamApps\common\assettocorsa\content\cars\abarth500_s1\skins

Simply unpack in C:\ProgramFiles(x86)\Steam\SteamApps\common\assettocorsa\content\cars\abarth500_s1\skins