I have been reading the various aerodynamic threads and it just reminded me of last year in winter. I was trying to beat a snow storm home from D.C. to Baltimore and some beautiful light flaky snow began to fall. It blew over my car like feathers. Due to traffic I had to slow to 35, but we picked up our pace and once 45 mph hit the snow flakes started blowing up like a plow in front of my car, the Solstice. As I accelorated to 55 the line of adhession was like a bubble, the air going straight up had started to angle back and contact of snow was now hitting the middle of the hood and going completly over the car. At 65 the hood was now equal, meaning the snow was covering the hood, but not hitting the windshield, the aerodynamics began enveloping the car and in the back of the car as the airflow rejoined, I had 2 rotating contrails off the back fenders.
So if your in an area that snows, bring a video camera and see if you can catch the speed transitions as air becomes effective and see how the aerodynamics change as you accelorate. Of course, be safe, the road was dry and the snow just began falling, good luck this winter.