It would be wonder if they last forever and easly could be repaired. Making it better to keep the car then buy a new one. It just need to be upgradedable to the latest standards that might be more safe, efficient and agree with current law.
But I am pretty that would never exist - too hard.
There's not much room for improvement in terms of efficiency for EVs, except maybe lower rolling resistance tyres and better aero. You generally have to replace the whole car for better aero though unless you don't mind having some bolt on mods 😂
Ok, but it might be in other areas. Example lets see someone invent very high efficiently on solar panels with no weight at all. Or lets get rid of rubber wheels and do sifi so the car can hover over the road.