so you can keep the windows open a bit while its raining without getting rain in your car yet having enough ventilation for windows not to fog. also its useful in the summer u leave the windows just a crack open so the car has some circulation i know we got the aux ventilation feature but hey u can never have too much. as for Barry i dont carry that on a regular basis so no i dont want a van lol but i figure i can just put the cover on when i go on trips requiring some protection