My daughter is about to purchase a used MINI. She owned a 2003 Cooper S for nearly five years until it was totaled. She loved it. Tried a BMW 325i sedan, now wants to go back to a MINI.

I recall that MINI changed its engine supplier (from Chrysler to ???) and has made other major changes since 2003. My general question is are there any model years to definitely stay away from? Alternatively, any model years to definitely try to get?