Since you said that, LF, I figured I'd show you where I am with design work on the dual rear-wheeled autotricycle design I started yesterday. Louisiana does not consider a three-wheeled conveyance a bicycle, and the motorized bike laws are quite specifically addressing "bicycles" (two wheels only). So far as I have been able to discover, three-wheeled bicycles (delta or tadpole) are a total non-entity under LA laws, which leaves motorizing one in limbo as well.WOAH! I can't wait to see this thing!
The law does define an autotrike, and since I want a road worthy vehicle that meets my needs, I figure I'll just design and fabricate the d****d thing myself. As shown, it's just the bare ladder frame and the the rear subframe. Note that as designed, the rear subframe remains normal to the road surface whilst the front suspension and the ladder frame is leanable, to 35 degrees off vertical either way. In addition, the rear subframe is so mounted as to be able to flex vertically through approximately 3.5 inches (shock absorber controlled). I'll likely add more pics to this thread as the design process develops.
Right now I'm contemplating a common axle with 3 hubs mounted for the rear - two 26 inch outer hubs and a 16 inch middle hub and rim moddified to run an industrial link belt from the jackshaft immediately behind the engine. I've found a new Robin America 5.5 hp 4 cycle engine for $199 ($0 shipping!), and will modify the engine mount between the pivot and the fender/shroud frame of the rear subframe as needed for that.