upgrade sub cord ?
 

I have recently bought the upgraded sub that came with the 2008 scion tc as an upgrade option for the premium sound upgrade. Its the sub that sits under the trunk liner next to the spare tire. I am buying a Kenwood ddx470 touchscreen head unit because my old one broke. I did not have this sub hooked into my previous head unit because it was a stock head unit. I went to the toyota dealership to see if they had the cord that plugged into this sub and went up to the head unit and they looked at me like i was speaking a diffeent language. They couldnt find the cord on their database and were less than helpful. I am wondering if anyone with the aftermarket head unit and the sub im describing could tell me what the end that plugs into the head unit looks like. Is it a standard rca cord like an aftermarket sub or is it a toyota version plug in into the factory wiring harness.