Aftermarket Stereo
 

Hi all. New to forum. I have an aftermarket stereo that I have hooked up but the power stays on all the time even with the car off. Now, I know why this is, because I have the main power for the stereo hooked up to a constant. I was hoping that the aftermarket unit would stay on until the door is opened like the old unit. Is this a function of the stock unit? Can I get the aftermarket unit to function like this?