Thoughts from a new BMW owner. I jumped at the chance to grab a 08 328XI from a good friend and co-worker. 73k on odo with 100k extended warranty for just about 15k (remainder of his payments; divorce and motorcycle to choose between).
My totally unbiased (I've only had it for like a month) opinion:
Fit and quality of finish: Subpar for what I would expect from BMW. More in line with expectations for a mainstream 25k Chevy, Ford, or vanilla Jap car. I do believe some of the parts for the 3 series are coming from China and have for years.
Engine: Mine is the I6 and its pretty damn perfect for what I need. Enough juice to have some fun but smooth and good enough gas mileage for a DD. I have confidence in it lasting.
Fun: Totally enjoy driving it and not because its new or and not because its a BMW. It is, after all a 15k car not like a 5, 7, or M. I'm grounded about that. The car just makes you want to drive another few miles.
Future: I keep seeing all this investment into smaller displacments and turbos. Not something I would drop the coin on new. No faith in turbo, especially air cooled. Liquid cooled gives me a better security blanket but that is just me.
IMHO at this point Lexus has em beat in the quality of fit and finish but IMHO just not sexy enough exterior designs to get me to cough up 50k or more. Funny I just said that, my wife is in a 48k Armada. Love it!!! But looks like a rolling brick.