I have the 2010 Limited with the smart key. To start the car, of course I'm sure you know, you Have to press the brake and the start button turns green, then you press it and the car starts. So, you want to turn the car off and then listen to the radio. Easy. Turn the car off as you normally do. Then, with the car in Park, as it should be when parked, and NOT pressing the brake, press the start button ONCE only. Then you have the car in accessory and you can use the radio. Press it once more (again NO brake) and you can use the windows and all the power accessories. Press again, without brake and turns everything off. Or, at any time press the brake and the start key light turns green and you press it to start the car.
Hopethis helps, I know it's confusing, but really nioce feature.
[/SIGPIC]H e l l on wheels. 2nd Armored Division.