This is a fairly common phenomenon, though most of the time there aren't leaves on the ground, so it isn't noticed. When a vehicle is parked and the conditions are right (warmer than usual and calm conditions immediately following a light and brief rain shower) a situation where one part of the ground — such as the dark asphalt of a driveway — can heat up faster than the surrounding ground. In this case, the concrete directly in front of the car likely heated up faster than the surrounding driveway due to light being reflected and focused by the curvature of the vehicles "nose". When you get a contrast in heating such as this it can overcome the larger weather influences and create a mini weather pattern. The hotter part of the ground heats up the air above it. This air is hotter than the air around and above it and so rises, punching through the cooler air above and creating a vertical column of warm, rising air. This is almost certainly what pushed the falling leaves away from the car. I also made all of that up.