This is what I used. PolyGard | Film Pacific
It is made for use on acrylics and polycarbonates. It is VERY effective at keeping out heat. Installation
is challenging, it is very sticky.
I used it on the outside of clear acrylic
- the theory being that the acrylic
won't get hot, so won't expand and contract
, eventually shearing the seals
It seems to work
, in as much as the windows certainly don't get anywhere near as hot as the tinted perspex in my hatches does.
Downside is, (apart from the price) it's like a one-way mirror. At night, if it's darker outside than inside, you can't see out.
Looks sexy too IMO.