We are currently on a road trip through South Dakota. We are from Central Canada and it is very flat, so the hilly terrain here is unusual to us. Yesterday we went through Bear Country USA. It is a very slow, curvy, hilly tour. A few times we needed to stop while the bears etc. cross the road. On one occassion, instead of using the brake while stopped up hill, I put it in Low and used the transmission to hold the Traverse.(I looked and it was in 1st gear). It was for no longer than 10 seconds holding in 1st gear when all of a sudden it dropped to a lower gear, I think, and rolled backwards......scaring the crap out of me because everyone was lined up bumper to bumper. Can you not use the tranny to hold you while parked or waiting up hill?? Has anyone else had this happen??