Making the Pattern

My first step was to make a pattern out of some 1/4" MDF I had lying around. I cut the piece of MDF to match the size of the basswood block and drew the outline of the car freehand to use as much of the block as I could. I located the 1" round window in a spot that I thought looked good and made sure that the axle holes weren't too high so the 1-1/2" wheels would touch the ground.