I've driven my 2007 X5 4.8i for close to 10K with zero issues. I've got less electronic gizmos on mine as you have, though. Had a 2006 530ixT for 2 years, zero problems. Also 4 other BMW's with minimal problems. Mechanically, these cars are generally great. Electronically, issues can and will occur but not across the board. Guess I've been very lucky as I expect them but don't seem to get them. Sorry for your problems, though. Seems like you might be close to a lemon law issue though.

Jeff