Hi, this is not true. I installed my DDX7015 initially wiring the speaker leads to the aftermarket "to-car" harness. You have to wire the amp turn on lead to the power antenna wire as well because the power antenna wire also turns on the amps, hence your antenna is always up.
So with the speaker leads wired to the amps you get acceptable but somewhat lousy and overly loud, hard to adjust sound. So what you want to do is take a set of RCAs and solder them to the "to-car" harness speaker leads. I took a really nice set of Phoenix Gold RCA heads and it worked out great. You could use a cheapie set of RCAs to do this. Then you plug it into the preouts on the new stereo. Just doing that alone, you get great sound from the factory amps and speakers, better than the factory stereo.
Replacing the amps and speakers isn't very easy for a novice. You can read the DDX7015 install thread to get an idea of whats involved. But replacing the factory deck is a piece of cake with the exception of the console trim plate. Anyone who's good with Bondo can make simple work of getting the stereo to fit just modifying the console trim. Your other option is the SOS trim plate but its expensive. You can forget about getting the color to match the original trim because the trim plate is electroplated and there isn't a color that can match it well. Rustoleum metallic black and a UV clear coat will make it look nice again.
