For the record, I do not agree with Carter austerity. I think we can have lives of abundance without the top 50% engorging ourselves with shiny trinkets. More labor should be devoted to basic needs and comforts of working class, not to the opulent pleasure palaces of red-faced affluent retirees and related creatures.
I think Carter was warning against finding self worth and meaning in material things, only for those things to never be enough and leave us broke and bitter. The car itself is a terrible mode of transportation but that cake is baked. We can only hope that intelligent software and autonomous driving can make car fleets more distributable so the notion of car ownership becomes redundant if you always have a vehicle on demand.