This idea is kind of out there.
Power brakes take energy to use, right? When stopped on an incline, I let the automatic transmission arrest my rearward motion. Those fortunate enough to have manual brakes don't have this issue.
I imagine the universal solution is the emergency brake. I've though about using it on hills that are too steep and when stopped on flat ground to keep the car from creeping forward. Just an idea...I have no idea if it works.
- LostCause