Has anyone had trouble with the rear hatch closing. I have to try several times before the auto closer grabs the latch

Might need an adjustment to the closing switch...

I either drop it from about a foot up or set it down and gently push for the motor to take over. It is much less "automatic" than the one on my previous Camaro.

With the doors and windows closed, the car is very airtight and you might have to slam it down a bit or, as I do, place it down gently and then press down with my hand or elbow. You'll notice that if a door or window is open, then it will close much easier.