35 seems a pretty reliable motor. Some waterpump issues, but this seemed a mfg defect- once replaced it isnt like they keep failing

Some transmissions had an odd 'lag' thing going on... hit or miss, fixes also hit or miss. Just pay attention when test driving. MAKE SURE you get the car fully to temp.

IMO if you are a DIYer, this will be no worse than any modern car. Give or take.

If you are serious abut buying a BMW, buy the iCarly first- will let you scan used cars and see whats up.