Imagine how boring the world would be if we refused every idea that didn't have an immediately practical purpose. Rocketry was probably overkill here but it did achieve at least one thing for the Tesla and SpaceX engineers: you can do things you did not believe were possible.
It does bring up the question of what’s left in car design.
RAM jets?
A car could get 10–30% better energy efficiency than a conventional car at the same speed. Initially, the air jets would reduce and then eliminate wheel drag, and then hold for safety maneuvers. At speed, off-wheel-lift would be generated aerodynamically, with the option to also spot redirect air pressure from the RAM jet, or the air jets.
Then 2.0 would be the fully redesigned one-eyed two-seated flying Tesla Bodywingster.
All for the environment!