Thanks for your response. I wanted to tap into a switched 12v, so the heaters turn off when the car is shut off. Here is the unit I purchased.
http://www.ebay.com/itm/Carbon-Fiber-Universal-Heated-Seat-Heater-Kit-5-Position-Dial-Ships-from-USA-/251013061269?pt=Motors_Car_Truck_Parts_Accessories&hash=item3a718b5a95