Robert Q. Riley has been designing, prototyping and selling DIY plans for innovative Build-it-yourself vehicles since the mid-1970′s.
The Tri-Magnum is a 3-wheeled car with a motorcycle in the back, a VW axle up front and body built by sculpting the car ouf of foam sheeting and applying a fiberglass skin. The car originally appeared in Mechanix Illustrated magazine, February 1983.
Riley’s fiberglass Over Urethane Foam contruction method works much like building a model boat or airplane, with the basic shape fist being defined by formers and stringers, then skinned in foam and covered in fiberglass. You get to choose the donor motorcycle based on availability, or to achieve specific perfomance or fuel economy levels.
If the Tri-Magnum is’t up your alley, you can also get plans for electric cars, hovercraft, RV’s, personal watercraft, whacky bicycles, submarines, and all sorts of good stuff. Link