David you must be running the whole route now with the car near completion! I wouldn't touch the windows they look great and are functional. Last summer was a bad one for bees out here and every time I had the kids in the car and windows down I'd swing the vent windows out as bees and other bugs can easily get into the back of the car at highway speeds... which did happen once. They also deflect a bit of the airflow for the passengers in the back as well. I don't see the gain with the work needed for the swap.