I vape in my car all the time, and I do get a film on the windows, but it comes right off with glass cleaner and paper towels. Need to get outside and clean them again, it looks a bit like it's foggy outside all the time lol. Nothing like smoke residue on windows though, I once bought a car that had been owned by a chain smoker, and they must have never opened the windows while smoking. Ended up alternating 91% rubbing alcohol and nail polish remover to remove the layer of tar. Had to completely steam clean the interior several times, and even then, after owning the car for two years, it still smelled like smoke every time I parked it in the sun with the windows up. Got a good deal on it anyway.. I would still be driving it but the transmission had other ideas and started acting up pretty bad at 194,000 miles. My current car doesn't smell like smoke and never will as long as I own it. But yeah... Vape residue is nothing compared to smoke residue.