By his own admission, Elon Musk's new flying road rocket is "not necessarily a safety-optimised car".Tesla recently unveiled a redesigned "Roadster" after nearly a decade of delays, but experts remain sceptical that it will be roadworthy in Australia.Loading Twitter contentUsing SpaceX technology, the souped-up sports car features built-in thrusters and a fan suction system capable of generating up to 2Gs of downforce.It lets the vehicle drive upside down, jump over other cars and perform mid-air rolls, acrobatics that would not look out of place in a sci-fi flick.The car can accelerate from zero to 97 kilometres an hour in less…