I figured this counted as a "scratchbuilt model"!
For our community theatre's production of Chitty Chitty Bang Bang Jr., I happily accepted the job of building the car. I had to scale it back mainly because it otherwise wouldn't fit on stage, plus being a children's show, the actors are smaller. The boat-shaped back is made from a cut-up sandbox, and the wheels are wall decorations from Michaels. I'm trying to be as accurate as possible. It won't be an exact replica, as I have a small budget and have to make concessions to whatever found materials I can use. And of course, time.