The Drive+play can be used wire directly into the head unit, or FM modulation. I believe (but not positive) that you can get an adapter that lets you plug it directly into the cd changer port. I was told this by the stereo shop and they actually showed me the adapter hanging on a rack, but I do not remeber the name. I believe it has been mentioned on this board before.

You also have the option of the "direct wired" FM modulation. This is where you take a splitter that puts the unit in-line with your antenna. I did this with an XM radio on another car and it had much higher quality than using FM the traditional way