i want to add subs to my 96 a4 with the stock delta headunit. i want to keep the stock look so im just gonna tap into the rear speakers with one of thoes rca adpaters. My question is, what should i use for the remote line?? Should i just install a switch somewhere upfront or is there an easyer way? I know by getting a new radio it would be way easyer, but i like the stock look in the car. Any suggestions would be helpfull.