Re: 100 mph topspeed.
I don't think this is as silly as it sounds. Imagine a 25mph headwind and going up a slight grade for a mile or two. Folks in the upper midwest states get this all the time. So now the car is pretty much maxed out to maintain 60 mph which is sort of reasonable for most hypermilers. However Joe and Jane Public will have the throttle to the floor the whole time so the vehicle better be built to handle that.
99% of cars today won't handle 100% throttle for minutes at a time but have the hp so they aren't used that way.
It would be cool if someone dropped a prius drivetrain into something like this and won:
