Lot of AM issues result from a bad grounding of the radio antenna..... People get interference with AM just driving close to or going under high line wires... I would say there is a grounding issue somewhere and that is causing your feedback.... IMO, AM needs to be phased out like analog TV.... I hate guys that come in and get a brand new radio and still just use it for AM and wonder why the reception is worse with the new radio.... well that would be because the AM receiver in your factory radio is actually better than an aftermarket radio's... Most Aftermarket radios have great FM receivers and some now have HD tuners which when a radio switches over to HD get really clear, and also provide you with station and song identification. I'm waiting to get a nice flip out with HD built in, when I splurge on that I probably will get sat radio, reverse cam, and GPS.... hopefully with most of it built in.... but that's down the road for now, my setup is pretty nice right now...