Alcohol works on mirrors but dries too quickly.
I am trying a liquid floor wax on the panels in the hope that I can keep the copier cleaner on the outside, but it take to long to buff and polish them. I carry standard windex spiked with extra amonia, be careful though, too much amonia in the mix seems to be kinda hard on the mirror coating. I have already done this and gotten the customer to move the copier to a better location. The location is at the entrance to an unground mine that uses Diesel for electrical power generation as well all motorized vehicles are diesel. Thereare some good suggestions here for you.