Uhmm maybe I dont understand your post Jordo... But If every single x5 has rear heated seats then I wouldn't be asking for the part number for the female connector end. I know on the 3.0 and possibly the 4.4 heated rear seats are not default installed, its and optional addon package.
I do know most 4.6 and 4.8 X's i seen have the option already installed ...It was part of the comfort or cold weather climate package if I can remember correctly.If your 4.4 has it then I am so sorry for not including the 4.4 in my post title. I have NA 3.0 06 and it doesnt have the female end ... Because I dont have rear heated seats....YET...wip

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E53 06 3.0i

wishlist
Comfort Seats
speckdock 2.5

Mods
Air suspension - wip
skid plate replica - in box
OEM sunroof deflector
OEM bluetooth streaming
navi,dsp,tv retrofit - wip
Low prof roof racks
2 directtv satelite tuners
Grom audio usb2
quarter and back window sunshades
2 10"subs- boxes opposite sides/Alp MRP-M850
rear heated seats retrofit
rear footwell lights retrofit
remote window roll up