Why no bicycles? if I stepped my bike up to 72v it should be able to do 45mph.
My comuticar is supposed to do 40mph with a good new set of batteries and with a few upgrades should do 40+, current is 35-37mph with snow tires, needs an alignment and has old abused batteries.
My last Super Mileage Vehicle would do 45mph, got 245mpg, but wasn't road legel, I did build it for about $600 tho.