Don:
Glad to hear you were not hurt. It doesn't surprise me that some people don't respect a moped.
Way back when I had rebuilt a Harley Sportster and was taking it easy on the break in. I was on a road with a 50MPH limit that people usually do 65 on because it goes over a dam and there is no cross traffic. I was doing 45 in the right lane.
In my mirror, the only other car on that road was coming up behind me. an older dilapidatd Buick. The driver came right up behind me for about 10 seconds then gassed it to pass on the right. The lane on the left was wide open. As you did, I kept to the left. As the car passed I was going to yell and flip the driver off, but this was the fattest, ugliest welfare mother you ever saw, with an equally ugly partner riding shotgun, and a back seat full of kids. I decided not to provoke Ugly into swerving into me.
You hafta ride like their out to get you, because it really seems like they are! That's the message to all riders on two wheels.
Jim