I don't think that your scenario fits what I'm seeing, as I can start the car and have the player start up asleep and then leave it asleep for whatever reason (usually the wife being in the car at the same time). Then park, turn off the car, leave the empeg in the dash, shop, come back, crank the car, and have the player start up awake. This doesn't happen very often, but it definitely does happen.

If it's the case that the player is just falling back on an old sleep setting, why would it get changed without intervention?