[SirSpammenot]

Disconnecting the Remote Control Door Lock Receiver mounted to the windshield directly behind the rearviewmirror will disable the keyless entry...

You could put a $2 switch in the plastic housing behind the mirror so you could flip the switch and disable the power to the RC-DLR. Then get out within your auto lock time, because for all it knows the fob HAS left the vehicle.. Later use the small/flat, non-electronic, key that fits in your watertight bag to open the door.. flip the switch and voilà! You can start the car.

Make it a black switch and nobody will notice it. Lock your teens out from joy riding... lots of uses!