I think that contest is more than 100x away from a useful car as most people would define it. It's at least 10x away in cruise speed and probably another 10x or more away in frontal area.

If you want to realistically get one person to and from work today at 125+ mpg with no more than a briefcase or laptop as cargo then a Honda Super Cub can do it. Beyond that you have to carefully limit the frontal area, top speed and maybe compromise on what happens going uphill.
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"If they can't picture me with a knife, forcing them to strip in an alley, I don't want any part of it. It's humiliating." - windsock