replacing factory ZHP stereo
Okay, some confusing issues about replacing the factory receiver with an aftermarket...
I stopped by a dealership today, and the salesman told me that if I get NAV for my 2004 ZHP, it would be pretty much impossible to replace the stereo with an aftermarket MP3/CD receiver. He said that if I wanted a new stereo, it'd be better to just replace the tray with a new stereo, so that I'd have two. But even then, since the NAV is hooked up to the speakers, I'd be better off not getting NAV.
Also, he told me that even if I don't get NAV, to replace the stereo would be tricky because of the hidden cassette player behind the face. He said if I replace it I might void some warranty.
I'm not sure how much he really knew about, well, anything that he said. Does anyone know if any of the above sounds right? I'd really appreciate any light shed on the matter...