This activity (on page 3 of the PDF under GPS: Sailboat Design Activity) is a full inquiry investigation into design optimization. Groups of learners will construct a basic sail car out of a fast-food sandwich container, some wooden skewers, and cardboard wheels. Construction paper sails of various designs and other adjustments are made in the course of several trials to develop the fastest fan-propelled sail car. Relates to linked video, DragonflyTV GPS: Sailboat Design.