2014 sequioa

Hi! I'm new here. We just bought our 4th Toyota, a 2014 Sequoia Limited and love it so far. I have 2 questions though. The back area when the 3rd row is folded down creates sort of a slope towards the back and stuff rolls out when you open the hatch. Anybody else irritated that it isn't flat...

All, I am looking for any advice I can get to get the best performance year round out of my Sequoia Platinum. I live in the Northeast and last winter 2015/2016 was our second full winter with the car and we ended up having to buy new tires because the truck did not handle at all in the snow...