Gscholz I assume the guy who flew the plane also designed it. Obviously it didn't fulfill the purpose he intended it for as it broke down while he flew it.
Define 'within reason' cuz a beetle that's designed for top 100mph going at 200mph doesn't seem within reason to me.
Cars that are designed for those speeds have different suspension, aerodynamics, brakes etc. for the sole reason of driving those speeds controllably.