I think y'all are over thinking the wiper/lock switch thing.
The easiest thing would be to add a resistor in a toggle switch set up to "trick" the ECU into thinking it's below freezing out!
I'm guessing the outside temp sensor wiring would be a lot easier to access than the wiper set up.
Off = normal outside temp/ ON = say 0-32* temps.
ECU thinks snow,,, more rear bias!
The easiest thing would be to add a resistor in a toggle switch set up to "trick" the ECU into thinking it's below freezing out!
I'm guessing the outside temp sensor wiring would be a lot easier to access than the wiper set up.
Off = normal outside temp/ ON = say 0-32* temps.
ECU thinks snow,,, more rear bias!