Robotic: Thanks, I will try grounding different parts to the chasis of the car. I have trouble finding an unpainted spot, but I'll dig.

Tony: No relay leaves me with only 1 headunit. I really like having the Alpine for radio/CD.

I wonder if the relay has poor wiring. I've already added Sony XA-39 II to my eBay search notification list, hoping I'll find that supposedly better relay.

Or maybe the car's wiring harness ground wire is too thin to handle three components. But it has no problem when I put the empeg RCAs direct to the wiring harness with all three components still powered and grounded.

The only difference between the Alpine (no noise) and the empeg (causing the noise) is: The Alpine's switched 12V line is wired to the relay and the empeg's is wired to the car. Worse, the empeg's switched line is wired along with its constant line to the car's constant line because the car has NO switched line. I'm going to tap into the cigarette lighter somehow for this.

But why should it cause radio static? When I had this problem in the Volvo, there was empeg "processor" noise and alternator whine, but the radio worked ok I think. Maybe because I'm using an antenna adapter?