Don, I'd get some of that reflective tape and make my own visual attractive display.
To the guys that are raising their own blood pressure because of slow moving vehicles---get over it. The truth is that there is nowhere you need to be that passing a slow vehicle causes any latency in your travels. If you're slamming on the brakes when you encounter a slow vehicle, you're driving too fast for the conditions and the physics of your vehicle.
I'm sure that Pianotuna is driving in the range of speed of most vehicles on the road. His pulling over for other motorists shows that he's conscious of those on the road.