Same thing happened here in semi-rural AZ last week. Heading for the post office and passed some girls flagging down cars and thought it was a HS car wash thingy.
Somebody was smart, as on the post office door there was a sign "Lemonade at the Dixie Maintenance Station". The post office is a mile past them, but more or less a high traffic area (for us).
Stopped and got a couple of cups from some thankful 13-year-olds. Dunno what the function was, just glad to see kids making some effort to earn some money.
Love it. That is America, FRiend...many an entrepreneur has a lemonade stand on their resume...:)