It seems to me that between about 20 and 40 there is no difference, but I live in FLA so anything below 50 degrees is getting chilly

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2006 BMW X5 4.8is Lemans Blue/Beige/Dark Maple
-Nav, Comfort Seats, Heated Steering Wheel,
Rear Airbags, AUX Input
2009 BMW M3 Space Grey/Black/Carbon
-all options