Today the pre-order bonuses for L.A. Noire were announced by Rockstar. They can be seen here.
List of pre-order bonuses
GameStop (US, CAN) Game (UK) EB Games (AUS)
Play (UK), Wal-Mart (US, CAN) JB HI FI (AUS)
Best Buy (US, CAN), Zavvi (UK)
It has been announced, that all the pre-order bonuses will be released as DLCs at "at some point after the game comes out".