2008 Buick Enclave drivetrain & axles problems

Once or twice a week my enclave continues to roll another 5-7 feet after being put in park and the key removed. The accident occurred when I was unloading groceries from the rear passenger door. The vehicle moved forward and ran over my foot. I have a 100,000 zero deductible warranty, as well as gm's powertrain warranty, but still zubor buick in taylor mi wanted to charge because they couldn't find a problem. Since my injury, I took it to another dealer today, red holman in westland.

While traveling on a florida interstate at express way speeds, the transmission just quit functioning. I had just gone over the top of a bridge, let up on the throttle, than pressed down again to maintain speed. The engine increased rpm's but I continued to slow down. This was with heavy traffic on my side and behind me. When I found room enough to pull over, I had slowed considerably causing traffic to swerve around me and caused panic braking on their part.