Looking at the XM systems. Saw the "roady system", I think by Delphi. It's nice and small. I'd have to buy the FM modulator that plugs in the cig. lighter. Is there another way to hook it up without modifying the interior. Installing an XM ready head unit is not an option. I have the factory 6 disk changer. Are there any inputs in the back of the stereo to allow connection to utilize the MD button that is of no use on the dash. I'm trying to make it presentable without blowing a ton of cash on custom installs. Just trying to figure out some options. THANKS!