Originally Posted by HPIA4v2

The two major issues on 545i/550i:
http://www.bimmerfest.com/forums/att...5&d=1268167349
and

SIB240309, need S/W update for trans lurching problem.
NEW SOFTWARE UPDATE RECEIVED 5-15-09 - 5 Series Forums

In any rate get the sport package, it has hydrolic Anti-Roll Stability ARS system, it makes E60 one of the best handling in it's class. This is not available in XI trim so make sure you can live w/o AWD in winter.

Good luck.