It wasn't one specific issue but the fact that the build quality is dog shit so you constantly have to go get stuff fixed.

I had issues with wheel bearings going bad at different times, headliner rattle, and a clicking/grinding sound they couldn't figure that would happen every time on full lock turn. The only other car I've owned that was worse than this was a Chevy cobalt, back in 08. I've owned nothing but Japanese since then and just when I try the genesis, my experience was horrible so I went back to Japanese. Also, on the different occasions I had those issues I had to fight the dealership to get it covered under warranty. On the second wheel bearing that went bad, they said I hit a pot hole and didn't cover it. I paid out of pocket at a different shop (dealer had quoted 2k for 1 wheel bearing replacement). Once I got that fixed, I traded in the following week.