cb radio causing interference

I have a customer who I installed a Clarion cd player four 4 inch Clarion speakers and a bazooka tube into a John Deere tractor.  Since then they installed a Motorola CB radio.  Now everytime they key up the mic on the CB it causes interference on the Clarion cd player.  It causes this interference while playing CDs as well as listening to the radio.  It even causes interference on just the bazooka tube with the Clarion completely unplugged.  I have no idea what to do!  Does anybody know of a possible fix?  IS there a possible fix?  I've tried different sources for power and ground for both units, I've tried noise filters, I even tried wrapping the Clarion unit in a ton of aluminum foil (don't ask).  Any help would be greatly appreciated.  btw the model of the Clarion is DXZ435 and the cb radio is a Motorola Radius M1225.

You need to determine how the interference is entering into the audio system. It may be coming in through the power or ground wires or it may be coming off the CB's antenna when it transmits. Temporarily hook the CB to a different battery for power and try it. If the problem goes away then it's a power filtering problem or poor grounds. If the problem persists then try locating the CB antenna in a different place and make sure to match the antenna to the CB with a SWR meter. The problem could be poor grounds on either radio or the battery to the body. The battery is a large noise suppressor (capacitor). Try hooking the CB directly to it's terminals.sparky