2000 jetta ?

I think, but am not sure yet, that it depends on which head unit you have.  As I wait for my G35 to be built (delivery in September!! ),  I'm gonna be driving around a 99 jetta that a friend doesn't need, and I plan to do as much as I can to the stereo hehehe.  If the car has keyless entry (don't know yet whether or not it does) then I will check it out and try to report back what I find out when I try to remove it.

I do remember at one point hearing from someone that there was nothing that could be done to retain the keyless entry functionality.  Unlike the GM cars with the Class II wiring, I don't think there's a "t-harness" available for these VWs which would let you relocate the factory head unit elsewhere in the vehicle and use an aftermarket for the sound.  But like I said that problem might only exist with cars that have the premium sound system option.