The Honda P 50 is the bike I saw.
It seems to be an obscure footnote in history now but when you Google Honda you are generally looking for motorcycles where as the P50 is a moped.
But it's what I was speaking of where the engine was built in the rear wheel.
When I studied Industrial Design, our instructors were quick to point out to us in the first days that there really isn't much "NEW" under the sun. So we shouldn't waste our time trying to invent new things only to find out later it had already been done before. (called reinventing the wheel) But rather to concentrate on learning about the most successful things which exist which could lend themselves to revivals, restyling, and remarketing.
So it goes with motor in wheel, whether it be be internal combustion or electric. Like I said, the idea goes way back and even some of todays heavy equipment uses motorized hubs.
What has to be watched for are those who use technology as con artistry. Whether it be a motorized bike motor, 150 mpg carb, a flying car, or a Dot Com movement.