How about just selling businesses signs that read "Driver's Welcome", have a recognizable design, and carry the message that they are welcome to use the restroo

How about just selling businesses signs that read "Driver's Welcome", have a recognizable design, and carry the message that they are welcome to use the restroom without buying anything? I don't know about urban core businesses, but in most places, it's already the case that no one working at McDonald's/etc cares if you walk in, use the bathroom and leave.