Could someone explain this? How would he hook up an amp w/out preouts on the head unit... are there any on the stock head unit? I am wondering the same thing so if someone could help, that would be great. I bought my X used and there is an amp attached to the backseat but not hooked up to the stereo. I'm thinking the person had some aftermarket stereo and just took it out when they sold it but I would love to be able to just wire it in. thanks.