I recently purchased a 2010 Buick Enclave when I am in drive on a hill the car rolls forward a great distance - it does not idle. When the car is in reverse while on an incline the car goes forward as if you are actually driving. It is not a little but a great distance. I took it to the dealership and was advised that is a characteristic of the Buick Enclave 2010 - that a hill stop assist was not installed. This to me is very dangerous I almost ran into the back of someone while on a hill and going in reverse and the car continued moving forward. I reported it to the Buick Customer Relations and they stated, it has never been brought to their attention.