I just bought my 07 Grand Prix which has the standard stereo. Would I be able to buy a direct kit to have XM radio through this stereo? I had bought a SONY explode XM ready stereo and all the components for it to work in my old car which I took out and kept before I got rid of it. If I could I would rather have the radio that came with my new car but if it doesn't have the xm ability I will just put my SONY in.