-Coasting not always engaging, even when going downhill in Eco at 50+ mph. 
-^... this then leads to the "meh" fuel economy.  It compares to my Santa Fe and other Genesis and Equus, but I've also had the Sonata Hybrid.
-The Parking Brake button.  Even after a couple of months owning this I still hesitate on what to do when I park.  Thankfully the Ignition also puts it in Park...
-The hood is maybe 3/8" higher than the front fascia.  Only a minor annoyance because I see it when I'm washing the car
-The cup holders.  I don't recommend using cheap styrofoam cups of soda or coffee in these-  Feel like they'll punch a hole in the sides.
-the 
wheel gap in the AWD model is meh, but I guess it's needed.
-Taillights. Surprised they didn't continue with the Genesis (G80) styling.