I've owned about 15 Bimmers (at least) over the years, the old 1600's and 2002's were great cars very simple, the Bavaria's and 3.0's had thheir overheating and camshaft problems, but the cars have gotten much better over the years..BMW's are "performance" vehicles...they have their problems...but are generally very well made. Proper care is important.
I like the 3.0 engines because that engine has been, basically, the same for eons...the V8's seem to have more "problems", and for me the 6 has plenty of power...so.
If your are looking at older Bimmers, their previous maintenace is important,
service records help, and a good PPI (pre-purchase Inspection) is well worth the $$

__________________
BMWCCA # 12660
14 GLK 350 M/B (hatefull POS gone)
05 CLK 500 AMG Cabrio
07 530xiT
09 Boxster