Considering buying an Optima... what should I know?

[lewisp]

Hi all,
Coming over here from the Buick forums where my '00 Century (195K) has finally earned its retirement. As you can probably tell I like to buy used cars and run them forever.
Am looking at several Kia Optimas, probably in the 2014-2017 year range. I've never owned one. What do I need to know? Any particular mechanical things I should check for before purchase?
Also considering the Hyundai Elantra and Sonata, same-ish years, I may go post this same question over on the Hyundai board, see if it's any busier than here...
Thanks much!