Hi joco1,
ARFs often have wrinkles. You can best use the monokote heat gun on high. Always keep it moving but some times you can slow down to get more heating. look For a slight color change in the covering it might not be visable in the dark colors. One trick is to heat around a bubble then heat the bubble or wrinkle. and don't get the nozzle of the gun to close 3 inches is pretty good. If you get it close move fast! good luck