During our recent heat wave, I got into my truck and the mirror temp was reading 111. Within a few blocks it dropped to 95, then to 89. Over the last few days it's been all over the place. Up, down, back up, etc. Exactly what temperature is it supposed to be reading (inside or outside) and where is the sensor? If it's the outside temp, I'm getting over 10 degree difference from what the local weather reading is (on the radio). I know there may be a few degrees difference but mine isn't even close.