2001 Convertible Radio Problem

[sjlawr]

This is just a thought, but I think it might help. Your stereo is probably picking up electronic "noise" from the engine of your car. This happens alot in many cars. I know in my mustang if I am listening to the AM stations, the radio picks up things like turn signals and wiper blades. At places like RadioShack you can buy a noise eliminator. I am not to sure how much it costs, but it could help. Also, make sure that the rear speakers are grounded properly, that could cause the buzzing as well. Good luck.