It seems to me that a physics genius would dream of a higher goal? Maybe like correcting the quantum theory? Assuming he knows what that is????????
BTW, we already have flying cars, their called 'airplanes'.......
He's not a genius yet, just very very good at physics problems and other related subjects. Becoming a genius involves alot of emotional and spiritual maturity. It also helps to be a bit crazy.
From the looks of things, he's a typical 8 year old with an atypical frontal lobe.