And it was ready to spray anyone behind it if startled. It kept driving like this for at least 4 miles, at which point I passed it. The driver was too oblivious to notice me trying to bring his attention to the very strange rear wing. Downforce? Increased airflow? I'm unsure. Regardless, it must be aftermarket. The last car I've seen do something like this was the old Abarth 600, and that was for engine cooling.... How curious.