I have a sirius that I want to install with out all the wires showing. I've put the antena under the clading and run it down the A piller I realy want to install it by tapping into the aux behind the dash so that the plug is open for the wife to plug in her I pod into. I also want to tap into the power suply and let the convertor stay behind the dash. but reading on the subject (all morning). I'm confused as what is the best method the pie ($$$) or tap into the aux :?