Dark tint will not work on Lexan. How do I know? I tried it, it bubbles like crazy after about a week. It even tells you on the tint box that it will not work (I didn't believe them).
If your door is a 30" entry door on a TT or Fifth wheel, the measurement of the glass is 12 3/8" X 21 1/2" X 1/8" thick. I had a tempered grey glass cut for both of my doors, replaced the "NO SEE THRU EM" glass. I then applied Gila tint "PLATINUM" grade from Lowe's to the inside of the glass. You can see out but no one can see in.
The Glass cost me $14.55 per door, tempered, grey tint.
Good luck