reasons a 2006 550i would go into safe mode and only uses 1st and 2nd gear

No I havent I don't have the funds to take it to a bmw service center

I just had two issues and both weren't as bad as I anticipated. First I had a leak in the transmission pan which was causing safe mode. Not cheap at $720 but better than a new tranny. Second was car would randomly not start, turned out it was $100 part basically looked like a fuse box, known to go bad on this model. Mine is an '07, since repairs about 7k miles ago no problems with the exception of squealing brake sensor also a known problem.