My brother had a friend of his install my car stereo for me and everytime you turn on the car, turn off the car, put in a cd, take out a cd, change a song on a cd etc etc there's this horrible sound, feedback from somewhere... how do I fix this??

 

How is it hooked up?
Speaker level input or RCA?
Remote on from ACC line, or from Remote out on HU?
What type of HU and AMP?

 

ha! Good question... I'll have to find out...