Got a note from Jack Fleming who is building a trike called the Roadstercycle. He has 2 versions, a 32 and a 34, which is 3 wheels 2 cylinders or 3 wheels 4 cylinders. The 32 is powered by a Harley Davidson twin cam while the 4 cylinder version has a Yamaha V-max engine. Handle bar steering, Wilwood disc brakes, they’re street legal in California where he makes them.
Interesting variations on the trike idea. I bet the V-max version has the right sound, too.