Motor Noise

I have a 2002 Dodge Intrepid and I installed the stereo myself. It sounds good but I have a annoying buzzing sound...How can I get rid of it...I have moved the RCA cables all around and yet I still get that noise...

Sounds like the noise is coming from the powersupply in the car. Get a noise filter and drop that in line in the power cable and see if that helps.

Also make sure that the system is grounded right