When I contemplate my '61 VW panel van parked next to my '71 SuperBeetle, I wonder what should park next to them. It would be smaller and exemplify German engineering and it would be nice to have something with a better fineness ratio than the BMW Isetta—something that would remind one of the VW 1-liter concept.
The Messerschmitt KR715 and KR200 sold in the tens of thousands. In the United States today (all due respect to the rest of the world) there is probably a population, the size of Germany's in the 1950s, that feels conventional automobiles' purchase price and operating cost are excessive — a potential market for a retro-mobile kit car.
The Messerschmitt offered 3- and 4-wheel variants. A side-by-side comparison of both versions would provide good data on the trade-offs of the two configurations.
Here are the basic components of a kabinenroller body—the monocoque shell and the nose piece.
All else required consists of the bolt on pieces, the front fenders, hatch and rear hood. At this point, I want to reference three articles at Autospeed:
Issue: 543/Section: Technical Features /11 August, 2009/Cardboard Cars?
Issue: 516 /Section: DIY Tech Features/3 February, 2009/Building an Ultra Light-Weight Car, Part 1
Issue: 517/Section: DIY Tech Features/10 February, 2009/Building an Ultra Light-Weight Car, Part 2
Small-scale manufacturing of the monocoque would consist of laser-cut pieces and glue. It could reproduce the original 50s styling, or one could customize it with Honda Civic headlights, fastback roofline and '59 Cadillac taillights (I need to Photoshop that), or one could re-skin it completely without the front fenders to resemble a VW Nils.
Right down to the gull-wing doors on both sides.
The stock hatch bubble pieces are reproducible:
Issue: 521/Section: Technical Features/10 March, 2009/Custom Bubble Canopies
Because the entire drive train is cantilevered off the back of the cabin, the wheelbase is variable. A tube sub-frame containing a 1938 BMW R72 flat-head flat twin (Chinese PLA 4-speed with reverse, please) feeding a narrow axle would put me on the moon.
The kabinenroller design has the driver's feet at the front axle line. An uprated version with the driver straddling the transaxle could have the drivetrain and front suspension of the Robt. J. Riley XR3 in front of the monocoque, so 3-wheel drive and 3-wheel steering is a possibility.
There exists a symptom it the computer-human interface world called Gorilla Arm. It's what you get when you use a touch interface on a vertical screen. It may be that using a control system like a recumbent bicycle has, with handle bars on either side of the driver's seat; or a joystick sunk into the right hand wall, would be ergonomically preferable. Early automobiles steered with a tiller that pivoted under the elbow, with your forearm resting on the tiller you grip with your hand. Just point it in the direction you want to go. With electric power steering, this could compete with a wheel.
But that's getting off my topic, so I'll stop here.