I was reading about protective films in the latest Diesel power magazine and they mentioned 3M had a window film that controlled heat but didn't tint the windows. Here's the link
http://solutions.3m.com/wps/portal/3...motive_Films/#
For those not wanting to tint your windows I think this would be a great product. I personally will be doing this to the windshield of the truck I buy. I'm confident I could get away with the CR90 on the windshield. Honestly not sure if I'd go with the CR40 on the rest of the truck because I like dark windows and the CR40 isn't dark enough for me. I may go CR90 and then regular tint on top. Honestly, I'm not sure. I just thought this would be great for people that want to control heat from sunlight in their cars. The fact that the CR90 can be put on the windshield and you'll get away with it really interested me.