Real, fake, its all subjective, its not being used for weight saving, its a cosmetic thing, if you like how it looks then youll do it, if not you wont, whether its real or not has nothing to do with it here.
for those interested, the 3M product can stretch as much as 75% more than its original size (of course you wouldnt want to over do it else it would look deformed) and its far cheaper than the Hasepro film