im about to purchase a factory head unit from a member up here in the classifieds but thought id ask a quick question first. does a factory head unit with a factory sub have preamp outputs or does ford use that t-harness i just read about in the "saleen sub" article? my single cd player wont spit out cds unless you beat on the dash above it some, so i would like to upgrade to a 6 disk and add 2 10"s, along with aftermarket full range (rear) and components (front). thanks