If you're willing to spend the time, you too can significantly increase the speed of most any aircraft. In Speed with Economy, Kent Paser takes you through every aspect of drag reduction using his Mustang-II as an example.(somewhat similar to Van's RVs) Flat plate and other types of aerodynamic drag are discussed as are cooling drag, exhaust systems, and over 100 other hidden contributors of slow flight. Highly applicable and interesting, even if you don't have the time.