a game you can play via mac, or any other os is the free 2 play online racing manager game. it is the biggest and best racing manager that came out recently. great work done by the devs.
http://www.myracingcareer.com/r19464/ try it out. it is translated to 22 languages already. great international community, over 50 different series, different cars, european series and also us series like indy car or nascar. almost all tracks in the world are present
http://www.myracingcareer.com/r19464/