Sounds like a software issue to me then. When turning off the ignition in the car, the player will stay on standby and obviously has a constant power connection. As long as you're not actually pulling the unit out, there should be power available with which to do any number of writes to the save area. Just need to make sure the logic and timing are done in such a way as to guarantee this works every time.

I'll just keep a close eye on the playlist position as I shut down to see if it happens again soon. It would be a huge inconvenience if it happened regularly.

Bruno