Not only can you purchase custom license plate frames over the internet, you can purchase oversize ones that allow you to put your personalized message in BIG TYPE.
I have had countless folks come up on my rear end and park there for a few seconds, and then suddenly back off and give me room. No brake-check, no coasting deceleration involved.
I think it might have something to do with the rear license plate frame that reads: "HOW FAST CAN YOU STOP?" Black frame with yellow reflective letters about 1 inch high.
Now, if I could figure out what to do about the vehicles that have the left headlight aimed up and out, focused right in my face as opposed to somewhere on the road ahead. They are bad enough with oncoming vehicles, but when they pull in behind you it's like a cop with his takedown light coming through the rear window. Virginia annual safety inspection just cares if the headlights work - no aiming issues. When I lived in Massachusetts eons ago that was a big item for flunking the inspection, as well as an easy $10 for the mechanic to fix for you on the spot so you could get reinspected. [/rant]
stay safe.
skidmark