I can’t recall the exact site where I found the idea for this, but here are a few links:
For our “cars,” I cut out the following:
Small black circles for the wheels
Medium black circles for the steering wheel
Small red circles for the horn
Medium yellow circles for the headlights
Red rectangles for the brake lights
White squares for the license plates
I also brought extra construction paper, glue, and crayons for the children to create whatever they wanted. One boy made side view mirrors and windshield wipers while another made a stereo and speakers.
Once the cars were created, the children placed cushions in their boxes and watched a “double feature” of “Danny and the Dinosaur” and “Harry and the Dirty Dog” while having their lunch and snacks and drinks provided by us.