I've wired up quite a few cd players for different cars, but all had a harness. I'm not sure what you mean by "t-tap"
. Could you explain? I assume this is a method to tap into the wire harness itself instead of cutting the wires and crimping the aftermarket radio's wires to it? If you have any pics of how you connected the aftermarket radio to the factory radio's harness I would like to see them.