For a month or so I let the kids bring in their tricycle and scooter and they ride around the house. One day I thought it would be fun to add some interaction to their riding. So, spur of the moment, I cut up a dollar store tablecloth into strips, stapled it to the top of a door frame (no one will ever see those holes) and we had ourselves a car wash!
They even set up a cash register on a little table with a tube from a rocket launcher and would stop and get gas there.
I got a little preview of my future as they kept asking me for gas money to put in the cash register.