I'm considering ceramic coating (CQ Finest) my white Model 3 (if/when it ever arrives). I'd like to coat the glass as well since my understanding is it will be like "permanent" rainX. With the all glass roof this seems like a reasonable thing. The thing I'm questioning is will this cause problems with rear window visibility? On my Scion FRS I made the "mistake" of applying Rain-X to the rear window. Since there is not enough airflow over the rear window, the rain just sits on the glass and diminishes visibility. Does the Model 3 have the same issue? Anyone have a wind tunnel available to visualize the air flow? Perhaps that is why a mini-model-3 is included - someone get that model into a wind tunnel!