Use your heat gun on these places. The covering will balloon up over the dent due to expansion of air. To get the covering back to level with the surrounding area just reapply iron but don't use a 'sock'. The sock compresses and any low spot will allow fibers of sock to push covering down into it. Hope this makes sense. Look at my Gallery page for the red racing plane is covered in film. It's smooth and wrinkle free. The graphics were done with film, too.