my BMW sevice usually is good. i goto keeler bmw in upstate NY. the guy i deal with is always good about getting me in at a good time and making sure my vehicle is getting all the repairs it needs...he even got me out of some...trouble with the warranty...and has covered my ass numerous times with keeping my warranty valid and not void. one of the things i think that helps is: 1) don't offroad your x5 and bring it to the shop dirty 2) make your SA more like a friend than an SA 3) make sure that you let them know what you want done but make it sounds more like something that you would like done instead of a demand 4) have good people skills 5) actually know something about your car and try to learn the parts and what they should do/sound like so you don't drag the SA and techs through a guessing game 6) dont abuse the warranty or freebies 7)make sure they know that you are glad you get serviced where you do and not somewhere else...

those skills should help out in keeping the service good. i have only had one problem and thats when the techs got mad because they lowered the skid plate and tons of mud and crap fell out on one of them...oh yeah, and make sure that the person you deal with isn't afraid to ask someone else if they dont know themselves. that's a great quality because it saves hassle.