I had one of those Honda 600s for about two years back around 1978-79 or so IIRC. Drove it all around, ran great, got 50 mpg! 4sp on the "dash" - shift linkage knob was actually mounted under the dash. Top speed of aruond 75-80mph. Great little car.
One day me, my cousin and two friends were in it, stopped at a traffic light on a fairly steep hill. I let out the clutch when the light turned green. The engine revved, but the car didn't move. Saw white smoke coming up the sides of the car. It was doing a front wheel burnout, due to the imbalanced weight distribution from the steep grade and loaded passenger compartment. yes, four people fit in there, no problem!