Hi has anybody had their door mirrors mist up when driving on motor ways? Last Sunday, when dry but patchy fog i stopped counting at 6 times, once when i was joining motor way which could have been very dangerous, one minute they are ok next all misted up then it clears. I know switching on rear screen with also switch on mirrors but this misting is so quick and always seems to occurs when you change speed. Mazda say that it has not been reported before and said they are not interested as this is a normal thisng that can happen, yet on all my other cars with heated mirrors this has never happened.