I'm putting it in an '02 Jetta. It has a double din, but I am planning on removing it and buying a single din since I can pick one up used for what the dealer sells a pocket/faceplate thingie for. I have an aftermarket amp already, I just didn't want to further confuse the situation by using it to power the factory speakers and I don't really wanna blow the cash on aftermarket ones. It sounds like you might be able to help me better than most. If I use an external amp, be it the factory one or the aftermarket one, will I still need an FM modulator? And if so, will it sound like crap?