If you're finding that your vape is creating a film on your windshield, there are a few things you can do to help prevent this. First, make sure that you're using the correct type of juice for your device. Some juices are more likely to cause this problem than others. Second, clean your device regularly. If there is build-up on your coils or wicks, this can also contribute to the problem. Finally, try using a lower wattage when vaping. This will produce less vapor and may help to reduce the amount of film that is created.