I've been trying to research this and posted my own Heated Seats question on July 27, without a reply. From my research, if the X3 does not come equipped with the Heated Seats option, the wiring is NOT there. I've been trying to determine if I can install an after market switch, module and wiring to a pair of X3 factory heated seats. The mechanics I've talked with do not want to try it. Let me know if you find something different.