You've probably seen this design before. Robert Q. Riley Enterprises turned out many variations of futuristic vehicle concepts that appeared in the pages and on the cover of Mechanix Illustrated for years, encouraging homebuilders to bring them to life in their garage. The Tri-Magnum looked really sleek and if properly built, was a nice "urba car" for high mileage driving fun. You'll sometimes see examples coming up for sale built decades ago that have been sitting and deteriorating, but this one was built just a few years ago and he obviously spent some time and effort to do it right.
It's powered by a 1982 Honda Gold Wing 1100 4 cylinder engine and includes a reverse gear. According to the owner, everything works. Seating for two is side by side. Shifting is done by a hand lever that incorporates the clutch lever. Gas and brake pedals are on the floor just like a normal car and it has a regular steering wheel.
They probably sold thousands of copies of the plans, but I'm guessing only a small number ever made it on the road like this one and in any case, you'll seldom see one in this condition, they more often turn up covered in dust in the back of some storage building, so if you're thinking you would like to have one without the effort of building it yourself, here's your chance to get a good one because it's for sale on eBay.