Mike, Thanks for your reply. I have been waiting for the temperature to drop but so far we are only at 4C ! It's a nuisance if that is the case because recent mornings the mirrors have been damp and on previous cars I would just use the heaters to clear them.
Did not realise my 2014 X3 did not come with heated wing mirrors. Can I retro fit and if so how ? Would the wiring already be there as mirrors already have cabling for electrical adjustment ?