Check out Lamin-X http://www.lamin-x.com/
. They make tinted film specifically for exterior lights.
I just did the fog lights & 3rd brake light on my 2013 Crew Cab Sport & it worked great (there are pics of the before & after of my fogs in my review on their site)
It's way thicker than window film & is designed to be outside. I haven't had mine on for long but so far it looks like a great product