ok,so most,if not all of us know the way to bring back the shape to a crashed and crumpled foam model is dip it in near boiling water for 30 seconds at a time,,as often as needed,until it comes back into the original shape....then most of us will also know that this leaves the foam with a slightly raised 'snake skin' look afterwards which although the foam will now be back into the correct shape, is kinda unattractive looking....
well,suffer no more!
the way to remedy this is after each dipping,use the underside of a spoon to rub at the affected area firmly,every where the 'snake skin' has appeared. this will smooth out the foam into almost its original texture. done soon enough after the hot water dip,and firmly enough,it will be almost as good as new.
dont expect miracles,there will still be some barely noticeable difference in the undipped and unrubbed area compared to the treated area,but compared to just dipping in hot water alone,the spoon trick makes a lot of difference in restoring your foam model back into that pre crash condition.
i always use this method and it works every time.(yes,i crash a lot!)
hope this helps someone.