'96 Audi A4 spkr pop w/aftermarket h.u.

Just did a '96 Audi A4 today using a JVC KDS590 and Metra's 70-1787 VW amp integration harness. Everything sounds fine, except for the loud pop whenever the radio is turned on or the station or track on the CD is changed. So far I've tried using a different deck, wiring various resistors inline with the remote turn-on lead, jumpering 12 volts to the wires in the regular VW plug(the one with power and ground), and changing from a 40VW10 to a 40VW53 antenna adaptor. Nothing has yet worked, and I'd greatly appreciate anyone's help; this vehicle's a real P.I.T.A.

I don't know too much about audio, but what about finding a better ground away from the factory harness? If ya figure it out let me know.

Thank you both for your advice...I won't have a chance to test the car for a few days. I'm kind of leaning more towards the turn-on pop problem there, but I also thought of another thing afterwards...the JVC 590 that we put in only has one set of pre-outs, and we had to use y-adapters...I was thinking that the drop in signal might be causing problems...not sure if the amps are turned on partially by signal or not, but it's something else to think about.