I installed it myself VERY SIMPLE to do, got nav system from friend

mounted gps antenna behind radio with double stick tape to underside of dash pad close to window in the center, and grounded a wire from the bracket to a ground source behind the dash. VERY SIMPLE TO INSTALL

nav system plays discs, no other changer in car, left M&T amp in and hooked up

I have a 04 Moon and Tunes Vibe, I was told you cannot swap the radio out and install the Factory Navigation System. The Dealer and Pontiac were WRONG. Pulled out M&T radio plugged in Navigation radio in left the amp alone, the radio sounds better than the original M&T radio. Now I just need...