The car player has two power leads, the memory maintain and the power feed.

Er, Rob, are you sure about that? As far as I understand, the main power source (the one with fuse etc) is the permanent one. Ignition sense is just that, a signal that tells empeg to go to sleep (and eventually fully off, if a timer expires without a user awakening it). After all, when one turns ignition off, the player merely pauses, lowers the amp command line and switches the dispaly off. If you wake it up, it plays normally.