Does anyone know how to turn off the automatic turn on feature in the Tom Tom R2. While the unit is in the car mount it turns on automatically when the key is turned on but it doesn't turn off when the key is turned off. If you forget to turn the unit off manually it could run the battery down. One of the four contacts in the back probably controls this feature but I am not sure which one. I know the 2nd contact from the left on the back side of the TTR2 controls the safety feature but I am not sure about the automatic turn on feature. Any suggestions???