The Double Bubble Bio-Diesel Trouble was a custom-built art car created by Don Schaper of Huntsville, AL, in 2006 for the Houston Art Car Parade. Built on the chassis of a 1980 Volkswagen Rabbit diesel, it featured a futuristic Buck Rogers-style fiberglass body and a five-speed transmission. With a narrowed rear axle, the car retained its original drivetrain, achieving an impressive 50 MPG, especially when running on used Krispy Kreme…