In this application, the weight added is a benefit. It counters the weight of the rear of the shuttle, understandably heavier just by the difference in shape.

With enough time and mess and muscle, Bondo does sand to a smooth and durable surface. The layer applied to the front of MINI Shuttle was thin enough to gain that effect without adding too much weight.

When finished her center of mass was almost dead center of her total length. She could be balanced on a single sawhorse.