Yes I too have had notes posted. "OMG where can I get one!" with telephone numbers...?
Took the advice of someone on this forum or somewhere. Now I post a one-page flyer on my dash with all the particulars. Sort of a smart FAQ. Seems to have worked. No more notes.
I keep a few spares in the glove box in case someone wants to talk smart and I need to take off, eh. Just apologize and hand them a flyer, "Sorry, wish I could talk. This'll answer most if not all your questions."
I'll send you a copy if you want it.
Rex