My 2013 Forester has 1000 miles on it, and I saw it roll a foot down an incline when it was in park and the motor was running. It would roll about 3-4 inches and stop. Within 30 seconds or so, it would roll again. I talked to the service manager at the dealership about this, and he said that he had seen the same problem on service ramps or when off-loading cars from the carrier.
He tried to frame it as a "design feature" that was not mentioned in the owners manual or in any literature he could cite. From an engineering standpoint, I would consider this to be a flaw and not a feature. I would expect "park" to be absolute.
I can find no reference to this in Subaru literature, and it would make sense that there would be a warning or caution if it were a known problem. I don't think the dealership knows what to do about this, so their tendency has been to treat it like it is not "a big deal" when they almost lost one car off a truck and one again later from their service ramp. Unfortunately, this is probably the same car that I bought.
I am concerned. Does anyone have thoughts or suggestions?