Hey im new to this site and audio so any help would be greatly appreciated. i just bought two 12in MTX Xtant subs and a PowerAcoustik Sp2x-820 amp for $30. im not trying to buy a whole new headunit but if i need to i will. so my question is, is it possible to hook up this type of system to the stock headunit in a 1995 Sierra (i dont have a CD player with it)? and where could i find some diagrams to make a box that will fit under the rear seat?