I don't know if this will work or not but, try turning off the sound effect that plays when the car shuts down. I'm thinking that the sound system is switching from radio to effects then switching back to radio at shut down. I'd try it myself but I don't feel like digging into the menus right now.When I'm finished driving and I turn off the car, the radio will go off briefly and then come back on until I open the door. I don't like this feature and wish that it would just stay off unless I decide to manually turn it back on. Is there a setting that will prevent this?