I've now had two MGF's and it was noticeable that when I jumped from the old into the new, the heater temperature control knob felt different. It appeared that when using the knob on the old car, resistance was only felt between the 12 o'clock and 5 o'clock (as opposed to between 7 & 5) positions, and correspondingly it was only between these positions that the heater temperature appeared to change. Problem is that the same now happens on the new 'F. I could dive in and try to diagnose the problem myself, but I guess that this may be a common 'characteristic' of the car. So if anyone knows, please reply!