I think part of the appeal of the M3W is its connection to motorcycles, especially naked bikes. I don’t think the Ford powered 3 wheelers had as much appeal. Using a fwd power unit from a small car would require conversion to rear wheel drive- not easy. This leaves BMW motorcycle power units. I first suggested the 1250 unit but after further research I think their new R18 would be a better fit. This is a new 1800cc power unit putting out 90 hp. If hung out in front the wide horizontal cylinders could be accommodated similar to the current set up. If the driveshaft were extended to their rear wheel it should be very reliable. They also have an electric powered reverse.
The recent spy shot however does not support my concept!