I will always have tint on my car windows. I just need to quit buying new cars so I can quit having to tint each one. The great thing about window mounts is that the window has to be down anyway, lol. Tint is really never an issue I don't think. If it is a problem the window will either go down or I will look at whatever out my front window. If I can't point the car towards whatever and it is raining I will hold something above the camera and mount it to the window anyway. Usually if it is raining the only thing worth recording, if anything, is possible hail..which, well, can be shot out the front. I've just always had tint and never really had much of any problems. As for night, again, if the window can't be rolled down it is very likely there it nothing worth recording. I think most states probably regulate front windows to a certain level anyway. A level that is likely a non-issue when pointing a video camera through it. I don't think I'd like shooting through a 'clear' window anyway.
The main reason I have tint is so when you stop at a stop light you really don't have to sit there and try not to look like you are wondering if the person next to you is staring or not. I so hate that when I'm in a car with no tint for some reason. I think Nebraska's tint laws say that the back windows can be down to letting 15% of light through while the front have to be 25%. I know, I had to replace the front ones. If driving through/around Blair NE watch basically everything you do. At one point I think we had the most cops per capita in at least the US(they train state troopers here I think).