I to have thought about a tadpole trike, but I start with a terratrike bicycle and add a 50cc honda GC50 and solar power... With full solar cell covered body work a la solar challange racers. Such a vehicle with a solar charging system at home would make me carbon zero and energy independent; almost... I dream that such a setup would get around 200mpg driving at night and better than 300mpg in the day for short trips, at about 50mph. The ultimat hybrid
. Your progress will be well wearth watching. Do you have plans for some solar on your project? What I have thought of is some way of useing a 120 watt, or so, solar panel as a body cover part, double duty as it were. This would also reduce the need for a large alternator system. When working on this type of project I always keep in mind a comment made by an engineer friend of mine who said that not being burdened by the facts can allow one to come up with something otherwise unemaginable!
and after you have demonstated that it works everybody then says it was obvious
...Keep on keeping on.