I got one of those belkin cigarette lighter/ usb chargers and it charges my phone and ipod but ive notice a buzzing sound coming from the stereo. The buzzing continues even when there is no cord in the usb charger but if i pull it out or replace it with the lighter the buzzing stops. Is there a way i can fix this by wraping the wires from the cigarette lighter in electrical tape? What do you guys use for shielding of wiring to stop interference?

When I'm listening to something loud this isn't such a problem but sometimes I like to relax with something more mellow and then the buzzing starts to become annoying and I just end up pulling the belkin thing out.

The USB charger is probably using some sort of switch-mode or PWM circuit to drop 12V to 5V without needing a big heatsink, and that signal is probably getting back to the stereo. The circuit will be operational anytime the charger is plugged in. Some sort of capacitive filtering would be required to deal with the feedback (the charger should include it, but the cheaper the charger the less filtering is fitted).

They seem to do that, haven't had much luck with those 12V to USB chargers.
An effective filter in the 12V line to the lighter socket may help, wrapping the wires won't.