I am the proud owner of an Audi A3 1.8 TFSI Quattro. I have noticed that the heated wing mirrors do not appear to come on when I switch the rear screen heater on? Do the wing mirrors work independently? When it is damp/wet in the mornings there is often a coating of condensation on the wing mirrors. My previous vehicles would allow me to get rid of this by turning the rear screen heater on? Am I missing something?