In the other window film topic I posted a link to a thread where people were having the same problem. There was a lot of talk about outgassing from vinyl and all the other dyed contents of a car interior. I'm sure that's a concern with a new vehicle. I used to see a blueish haze when I smoked. That came off pretty easy, but it wasn't a PG/VG vapor like we encounter with vaping.
I remember the slickness of fog machine juice when we used one in our band. After almost sliding down the first time we used the machine on a hardwood stage, we decided that in the future we'd only use it on carpeted stages. It left a dangerously slick film on the stage floor. I can see how it would accumulate on car windshields.
I vape with a window cracked every time I drive. It still collects on the windshield, but white vinegar takes it off quickly if you used balled up newspaper to remove the vinegar.