I've been working on this issue for a couple of weeks now, gradually upgrading components in an attempt to get it to go away.
After an amp and speaker upgrade to the base factory stereo, I had:
1. Static.
2. Whine.
3. A radio station in the background with the radio off. Seriously.
I focused on grounds, grounds, and more grounds with everything I'd installed. I even bought some top shelf RCA cables and better line out converters, going so far as to connect them directly to the speaker level output at the factory head unit.
After two weeks of no success, I just accepted that the problem was with the factory head unit and/or wiring. Since I'd already torn into it, I knew that I couldn't expect help from the dealership for a warranty issue.
I shelled out some serious coin for a PAC dash kit with harness, and a double DIN head unit.
After the swap last weekend, I was left with the static and whine. The background radio station vanished confirming that at least some of my problems were from the factory set up.
Again, I focused on grounds, grounds and grounds.
Only after I wired the head unit to get power directly from the battery did I make any headway.
But you'd think that a good ground is a good ground and that a solid frame connection would be as good as the factory one, which was noisy in a previous troubleshooting step.
Oh well...score one for Easter egging your way through a problem. //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif