Request for help - heated rear seats




Long story short but when i order my car heated rear seats weren't (and still aren't) and option on UK (RHD) cars - which is quite shocking for really for the type of car . I am going to retrofit by likely using one of the aftermarket kits and placing the switches on the rear console above the ashtray flap.
Questions/Help needed:
1. I have removed the rear seat base and can see how to remove the cover, can someone please provide me some instructions about how to do the backrest (S213 Estate model).
2. There is no wiring under the seat so i guess that the original loom wiring connector wasn't put on the car but could someone post the wiring diagram for the original heated seats circuit.
3. Could someone provide me with the part number for the original seat heater mats - i might then be able to use them but connected to the aftermarket swtiches?
I know this is not to everyone's taste but grateful for any other useful info.
Thanks


