You can always play around with an old motor you don't care about, or just try it out with a $20 machine wound mod or something you don't care about killing the magnets on.
Obviously higher voltage motors exist, I just don't know how many in a form factor common to most cars. That place does SERIOUS drag motors. Maybe you can find someplace that does less insane higher voltage motors if you're just messing around ?
Criminal, it says on thier site figures like 90MPH TC3 (145 km/h) and 112 MPH (180km/h) in a quarter mile run and such. Those things can apparently move a car quite rapidly.