Just got work from Rockstar that a patch for Midnight Club: LA for both Xbox 360 and PS3 is available. Full release:
A title update is currently available for both the Xbox 360 and PLAYSTATION 3 versions of Midnight Club: Los Angeles. Both updates bring improved AI balance to adjust dynamically to user skill level. The Xbox 360 update also adds support for additional leaderboards for tournaments on the Rockstar Games Social Club, broader multiplayer match searching, and upgraded streaming and performance.