Winter (and fall) fuel economy refinement is a must, that is by far my biggest, and really only complaint.

Center console and armrest.

Built in cellphone holders/chargers/integration. They're building all the machinery into the car and that, in the end is somewhat silly. If they just had better phone integration, you wouldn't have to worry about the car system failing. The phone will fail and be replaced easily, and likely at far less cost. On a side note, I really don't know why cellphone chargers, like a female USB in a good spot isn't the norm. The only vehicle I've ever seen this done well was a new (and very expensive) dodge ram.

Better Radio Reception and louder speakers (the speakers they enhanced in the 2015, from what I know.)

Sound dampening refinement for the engine (I don't know if they fixed this in the 2017.)

Better materials for the trunk (I don't know if they fixed that in the 2017.)

The side buttons on the 2014 also don't light up, it's somewhat annoying if I have to adjust the mirrors on the go, There is no way to see them at night.