I am trying to add the factory heated seat option to a 2007 Mustang that did not originally come equipped with heated seats View attachment 137305 . Has anyone managed to add the factory heated seat option? On one of the Mustang forums some time ago, I came across a thread where somebody put together a list of all the parts needed along the part numbers, but can no longer find it. I picked up on Ebay the HVAC control unit that has the heated seat buttons and also picked up the (4) Ford View attachment 137307 heated seat pads. I know there is also a relay and additional wiring harnesses needed. Anybody have part numbers for the relay? Any pictures of what the relay looks like or where it is located?