To be absolutely honest with you guys, the bimmer loaners are available:
1) if there are more bimmers to give to customers...no one really want to shell out additional $$ from the dealership.
2) believe it or not, at the mercy of your service advisor....hence if you treat them nice they will be nice to you.

I personally have great relationships with Stevens Creek BMW in CA...though some have complaint. The service advisors when they see me know me by my first name and even the service manager knows me. I asked them why they are so nice to me is because I treat them with respect and courtesy...not because I own a "BMW" and become snobby because "I have status now".
So I want to point that out, not saying anyone of you guys are bad, but just want to let you know that they are human and sometimes they have good and bad days.