Having the same issue! Loud noise/thumping/rumbling/vibrating
On 11/14 I came out from work after my car sat for about 6 hours, hit the unlock button and the whole car proceeded to shake/convulse and make a loud thumping noise. It went on for about a minute and I honestly thought the car would explode! (Dramatic but it tells how loud and crazy this was). I touched the door handle and could feel the car shaking. Then it stopped and I started the car and everything seemed fine.
Today (12/4) it happened again. Car sitting for a few hours, hit the unlock button and very loud crazy thumping noise. I never hit the automatic start, never turned on the car, just hit the unlock button. What is this?? The car is with the dealer now but they want to see it happen. Well, it has been about 3 weeks since it last did it so that is unlikely. Maybe the scanner will show but they say that is for engine events. Doubtful that this is an engine thing - doesn't sound like it and the car was absolutely not running.
I really hope they can figure this out. I wanted to add my voice here to show that others are having this same issue. Help!