I replaced my stock stereo with a newer one and rear speakers stopped working. Various places told me that I would have to bypass my factory amplifier in order for them to work again. It was gonna cost me about $100 to do so. I called Joe and asked me what kind of stereo I had, he asked me to stop by his shop and maybe I can avoid all of that. I ended up going and all he did is play with my stereo settings and rear speakers started working again. It's clearly that he knows what he's doing, by the way he didn't charge me anything either :)