This is from the site Bring a Trailer (https://bringatrailer.com/) ...
This 1984 Tri-Magnum is an early Honda Goldwing-powered trike kit that takes its model year from the donor bike. The seller says it was completed seven years ago following a two year build process, adding that it’s fast and handles well. Plans are still available for this kit, which apparently incorporates a standard VW Beetle front end mating up to the donor two-wheeler’s frame and drivetrain (minus front fork, fairings and such) via some sort of custom bracket. This one actually looks pretty cool, but with “no reverse, no heat, and no air conditioning,” not to mention no opening windows in its tilting, one-piece canopy, some further sorting will be in order to make it usable for more than a few minutes at a time. Find it here on eBay in Fairfax Station, Virginia with reserve not met.
The Suzuki mudflap is a bit misleading, but these kits were apparently designed to take any number of donor bike transplants. Styling is very 80’s, but actually pretty well resolved around the rear 3/4 angle. Taillights look a lot like Cortina items but aren’t, and we like the way they tuck up under the bodywork like jet nacelles. Graphics and wheels are well-chosen, but that canopy needs some ventilation added to make things livable inside the cabin–fortunately simple, flat sides with a fairly large surface area should make this fairly straightforward.
The cabin features a seat with two headrests, but it’d be awfully tight with a passenger inside, and the seller has fitted an instrument panel, sequential shifter, and what looks like part of the donor bike’s hand controls where they’d sit anyway. The seating position is pure early 70’s concept car.
The engine bay isn’t photographed very well, but looks like it could use some tidying anyway. This is an earlier, flat-four version from a 1984 GL1200. and should be good for around 94 HP and 78 lb. ft. of torque.
From ’87 on, the Gold Wing switched to a flat-six design with electric reverse which could be very helpful here–the extra ~6 HP and 32 lb. ft. of torque would be welcome too. Still, with a bit of tidying things could present much better in back, and being a Honda it should be reliable and easy to work on.