Yes, I currently have panel 16, above, which flips open to reveal a power outlet and the Aux In. There is nowhere else to install the switch.

I believe that panel 16 is not used with the seat heaters, and panel 21 replaces it, in conjunction with 22. I just haven't seen one to know for sure. I could drop by the dealer and take a look, but if there aren't heaters in the seat cushions it is a moot point.

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2007 X3 3.0si, 6 MT, Premium, White

Retired:
2008 535i, 6 MT, M Sport, Premium, Space Grey
2003 X5 3.0 Steptronic, Premium, Titanium Silver
2002 325xi 5 MT, Steel Grey
2004 Z4 3.0 Premium, Sport, SMG, Maldives Blue