After six months of hard research, I crossed off anything newer than a 2009 model. In 2010 issues started showing up with things like recalls to replace piston rings due to high oil consumption and other issues I consider high risk, and Gen4s only add to the list. IMO the added tech gimmickry only adds to the problems and expense of ownership. In the end I wound up with an '07 with 92k, and couldn't be happier, although I really wanted a manual transmission but was unable to find an '05 or '06 manual in good enough condition. I think I will have fewer issues and a lower total cost of ownership with my '07 than I would have with a Gen4. But if I was limited to one, I wouldn't go newer than a '14, as issues went up exponentially after that year. Also, I will never own anything with a CVT. They are junk IMO. More expensive to repair and less reliable. I already see other carmakers reverting to multi-speed automatics from the CVT. Just my opinion, but I did a lot of research. A lot. No, really.
Beyond all that, common sense is king when choosing a used car. Buy only from an individual, never a dealer. Look for appearance and condition, mileage and records, and an honest seller.