dude, truthfully if they are grounded properly and u made sure they were (your not going to like the answer) some cars do emit a slight hum noise but never static.
i have had installers work on cars and the same thing happened but the noise never really went away they could just make it lower...
i was searching for a new series and the amazon reviews on this series are good. but i am afraid to buy it i don't know why.
it's getting difficult to find a book i like, does that happen to you?