How do you get the seat bottom to angle flat as noted in the post by the Zip? I just purchased a 2017 Yukon SLT. Just as everyone's posts say, when the 3rd row power seats are folded down as flat as the electric motor allows they are nowhere nearly as flat as GMC's nice little color brochure pictures portray. In reality, the right or passenger side third row seat back folds down much flatter than the drivers side but the passenger side is still by no means flat. And the drivers side seat back of the split bench is 6-8" less flat than passenger side. I've checked and made positively certain that there is ABSOLUTELY NOTHING laying around blocking full travel of the seat backs. What is the problem and what if anything can I do to make this things lay flat?