power outlet off when car is off?

I have a 2000 LX 3.8L. I want to plug my GPS unit in the car cigarette ligher or power outlet and be able to leave it plugged in when I turn off the engine. However, these outlets do not seem to be turned off when the ignition is off. Have any of you manually wire these outlets to have them switched? also, what is the difference between cigarette ligher outlet and the power outlet on the side?

Thanks

I know that the lighter on the dash stays ON when the ignition is OFF.
Mine is a '96, I have a lighter on the side, behind the driver's seat in the radio remote module, but don't remember if it stays live or not.
I am guessing that the engineer at FORD who set the lighter circuit up that way......many years ago before we started calling them "power outlet".....was a serious smoker.