Unfortunately, Permenant tracks of Sun Valley, Crystal Park, and Revelation Close its doors. CP believe the lease had expired, and wont add on few things to keep it opened. Revelation started Off-Road racing, SV well!
GLARCC is probably your best bet. They hold there races at on of the Metro Stations, I thick in Carson or Compton. Think they hold races every 2 weeks. If you are ROAR Member you can find more info om WEB.
Why Are you asking cuz you're in Shanghai???