What would the dealer plate do? I've seen them around but what exactly does the plate mean?

 

Ha Ha Ha!
Throw the letter away and continue to do it like you like it!

Even in the Peoples Republic of Cali, they have to have more proof than some other citizens word. That place is so depraved. Who would even think of such a lame program as telling on your fellow drivers so they can try to intimidate them with a letter. It is reminiscent of programs in totalitarian states were you can inform on your fellow citizens if they are saying things against the goverenment!

 

Well this is the socialist state of Democratus.