I have a 51 plate E46 330d auto estate,138k miles and mechanically it's been spot on. It's got Full BMW SH from new until I bought it then my usual garage took over servicing.

Had it four years now and my only problem was an intermittent starting problem that turned out to be camshaft sensor. 80 quid to replace.

I have other little problems though e.g. Remote key fob has stopped working, door lock has collapsed twice (easy repair though) and rear wiper has seized up.

Driving wise its been the most reliable car I've owned, fairly quick and a great cruiser.