You can get special type for plastic windows, but you don't need to.....
I just used a proprietry one for normal windows (house or office) on my plastic Hitop side windows. Came from Ebay and IIRC was only about 20 quid for a 6 metre roll.
They had previously had a really dark blue film on and when that was peeled off there was very sticky residue.
I carefully used nail varnish remover (acetone) on one invisible corner first, no puckering of the plastic so all good to clean off old adhesive.
Is your window double glazed? if so there is a bit of a trade off, in order to get the new film on flat, you will have to remove any breather plugs present. Of course that leads to moisture getting in between the two sections and you will need a lot of soapy water to get the film on flat with no bubbles.
I was lucky that I could strip mine down completely and once filmed, left to warm up and dry out in the sun.

The patterns area result of me trial fitting it and leaving it in overnight, it's just condensation between the double glaze. All dried out now though
I intend to do all the other glass (that I am allowed to) in the near future but the rest of the van is easy as it is all single glazed.
(Still want to take the glass out to do it all though, so much easier out of the van than in it)
Good luck
Jon