interesting, but i still need more details. you are not interested in the door speakers, correct? it is the front (i assume the dash) and rear deck speakers that you are wishing to improve, right? assuming that the front and rear speakers are driven directly from the deck, you are dealing with a high level signal. if those speakers "can fade", then i would assume that you are also dealing with 4 channels (does the deck have a fader?). if you do have 4 channels, then in order to preserve the fader function, you will need 2 amps (or the capacity to run 4 channels, ie 4 channel amp). if the only practical place to put the amp(s) is in the trunk, then you will need to use two line level converters (about $25/ea) connected close to the deck, run the RCA cables to the trunk, run the speaker wires back to the front (***see trick below***), and connect close to the deck (where you spliced in for the line converters ). ***trick***: the rear deck speakers can obviously be wired directly from the amp; do that. now use the factory wires from speakers in the trunk and connect those to the front outputs from the amp, remember the colors, and connect those to the cut wires to the front speakers. this way you do not need to run RCAs AND speaker wires from front to rear. and believe me, the factory wiring will work very well and it is ALOT less work and hassel. if you dont have 4 channels running front and rear, then, as you wish, i can advise you further. keep in mind, in the event that you want to upgrade in the future, the bulk of the work will already be done if you follow my advise. sound like alot of work? it is but it is not that difficult and you will know that is was done correctly. if it sounds too much, have an installer do it, but beware of them trying to get you into something more expensive. the "entry level" MTX amps are cheap and sound great. good luck.