I can't speak from direct experience but my aunt purchased a 2004 545i series and it had a computer or module glitch in it. When cold, sometimes, the car would light up EVERY warning light, get stuck in 2 or 3 gear and only run about 35mph in limp mode until reset. It also was the first year of active steering so it wore the inside front tires very quickly. She traded it quickly!
Just things to keep in the back of your mind when looking at older used BMW's. Do your research, and read some 3 or 5 series blogs before committing. Good luck!


Cheers,
KrzyFast