According to Consumer Reports, the 2010 335i has a "worse than average" repair record. Older ones tend to be "much worse than average". But that is probably due to the HPFP issue, which by itself is rated "much worse than average", which would drag down the overall ratings.
I think it depends on the following:
(1) How has the car been treated? Some on these boards believe in breaking them in with a "drive it like you stole it" philosophy. And some that lease figure "I can drive it very hard because I'm turning it in before the warranty runs out". But the vast majority probably treat their cars well.
(2) Has the car been modded to get more HP and torque? Who knows what the long term consequences of that are?
(3) Have the fluids been changed regularly, especially the engine oil?
(4) Has the car been tracked or raced on the street?
(5) If it's from a cold climate, has salt caused any rust?
The bottom line is that:
- It's important to get used cars checked out by experts on the make and model.
- 335i's are probably going to have more problems than most.
- Is it worth the extra inconvenience and expense to enjoy the thrill of spooling up those turbos and driving a great sports sedan or coupe?