What do you mean by flash the radio ? Don't think I really care about fade.

 

By "flashing" the radio, the dealer can reprogram it to enable features that you don't have on a stock SG. Like Iron Cross said, you have signal coming out of the rear pins on the radio but you don't have the ability to fade between the front and rear.

Here is a neat little adaptor to get the rear signal without ordering all the separate parts and making your own, or buying the expensive overlay harness.

http://www.vtwinaudio.com/store/prod...eaker-outputs/