Absolutely, seat warmers are typically nothing more than a resistive grid under the fabric. A quick check for how power's supplied in case there's a requirement for current control, and wire in a physical switch.
Unless there's something snuck in that throws codes if the seat heater does something unexpected - wouldn't that be something, DRM for Bimmer bun warmers. In which case if it's not possible to fool the system by wiring in a resistor instead, then it's a car to avoid as seat warmers are rather prone to broken traces over time from occupants bouncing and shuffling around on the seats, which could render the car unregisterable in regions that check OBD codes.
Unless there's something snuck in that throws codes if the seat heater does something unexpected - wouldn't that be something, DRM for Bimmer bun warmers. In which case if it's not possible to fool the system by wiring in a resistor instead, then it's a car to avoid as seat warmers are rather prone to broken traces over time from occupants bouncing and shuffling around on the seats, which could render the car unregisterable in regions that check OBD codes.