Thanks for all the replies, folks - ScoUK in particular for all the detailed advice
Just one question: The tints that you guys have removed, had they been 'professionally' applied?
The reason I ask is that when I first bought the car, the tints having been applied before I bought it, I had a wee try at removing a wee corner of the rear windscreen film. Even after minutes of exposure to the heat from the hair dryer, it hardly budged at all..... only got the corner back by about a couple of mm, then decided it'd be better to leave them alone!
I dunno... the film seemed very hard and very reluctant to come off. Nothing like removing a window sticker.
Any opinions are more than welcome - just don't want to make an erse of it!
Cheers again
P.S. Regarding residue, I have some label remover in an aerosol, which usually does a good job of breaking down adhesives.