My CD player has an aux in on the back and I took it to a spot to have it hooked up. They drilled a hole and let the cord run in this slot under the cd player and out the front. It was only like $20 plus the cost of the cord, which can be bought on ebay under $10. Lots of newer CD players have the aux in jack right on the front now. 100x better than a shitty FM transmitter. Fuck those things, they drive me crazy.