Galifianakis and Cooper Weathering the Storm

10/25/2010 2:50 PM PDT
Days after  Mel Gibson was axed from "The Hangover 2" thanks to cast pressure -- co-stars Bradley Cooper and Zach Galifianakis teamed up for a for a different reason ... to party in Hollywood.

Brad and Zach were mum about their new castmate Liam Neeson as they left the Chateau Marmont last night -- running for cover from the weather -- but what they lacked in verbosity, they made up for in pimp rides ... a Toyota Prius and a Subaru Outback.