Is there a chart or something somewhere where I could find out what engine I have? The information on Wikipedia is suspect.

a quick search for "bmw engine faq" (in this forum, not google) yielded:

http://forums.bimmerforums.com/forum/showthread.php?t=89822&referrerid=&highlight=engine+faq

Doing a "find" in that thread for "e60" yeilded no results. Still don't know which engine I have.

FWIW, Dealer says it's an M54 engine.