I need a full length mirror in my dressing room! My closet doors are frosted can I paint over them with mirror paint?
Mirror paint does not work that way. It's not a surface coating, it has to be molecularly smooth and that can't be painted on.
Generally mirror coatings are on the glass itself, and on the backside. The fogged glass has already wrecked the possibility of doing that. Feel free to obtain actual mirror glass and replace the glass in your cabinets, be careful.