Start a class action with GM.Oil leakage? Northstars leak from bottom from 40K. on 2005 Cadillac DeVille

This engine on cadillacs has reputation for leaking oil from bottom. Have remove engine to repair problem. It appears to be design problem. Cadillac will do nothing. I have written, called and etc. Nothing they will do.
Is there anyone that will join in class action against GM?

Asked by for the 2005 Cadillac DeVille