Lewis's car modelling tutorial is a pretty good start point
http://www.lwg3d.org/forums/showthread.php?t=14554
Then Unknown Limit has done one as well:
http://www.lwg3d.org/forums/showthread.php?t=14472
You can see Lewis's work in the gallery section here at SimplyLightwave and Unknown Limit is currently working on another BMW in the WIP section here.
