I was a motorcycle rider prior to getting into bicycling, an upright vertical figure is sometimes almost invisible to people. I was invisible to a LOT of drivers on a wide fat Honda Goldwing, I am damn near invisible on a tall skinny bicycle. People are just looking for something wide and lower in their minds eye and complete tune out the upright figure of a cycler. Using the lights and horn is about all you could do. Congrats on the recovery, it could of gotten nasty real quickly.