The change in value perception is one of the factor leading to a change in the economics in the transportation sector, not the only one but surely an important one. If the market, people, no longer perceives a value in the ownership of a car, clearly that companies selling cars are facing a problem.
There are other factors as well.
First of all the shift to transportation as a service dramatically reduce the number of cars needed. Today cars are sitting idle at least 90% of the time (according to transportation adviser Paul Barter in the US a car is parked 95% of the time). By reusing cars the needed number can decrease to as low as 40% in a city (to provide service during peak hours) and to 80% in the countryside (where density, hence sharing possibility is much lower). On average the car manufacturers expect a decrease in production in the order of 50%, with a higher decrease in margins since the private owners will become scarce and buyers will be by far big corporation managing the transportation service. Just in the 2015-2030 time frame profits in cars sale are expecte to decrease by over 30%.
Related to that we can expect a collapse in cars advertising (no point in advertising trains today, no point in advertising cars tomorrow!) and a sharp decrease in tax revenues on cars and on gasoline, since the future autonomous vehicles will be electrically powered.
Today oil demand is driven by the transportation sector, using over 50% of production (cars 20%, trucks 24%, other 12%). Oil demand from cars and trucks will sharply decrease from 2030 on (electricity will likely be produced through renewable sources already getting chaper than oil and with a price on the downward in the next decades). In the transportation sector, oil will remain the fuel for aircrafts (electrical aircraft have been demonstrated but we are far away from a commercial exploitation in the first half of this century).
At the same time as market shrinks in several transportation related areas (including the ones like insurance, infrastructure components -red lights, signals,….) we can expect the decrease in transportation cost and the increase in its efficiency to shift the retail to the cyberspace.
Cars can double back as transport platforms for goods during night time when demand for people transport will be very low. Automatic loading and unlodating of goods, integrated in the houses/homes will make home delivery a breeze sealing the fate of brick and mortar shops.
The good news is that plenty of money no longer used for transportation will become available fuelling other sectors, changing the economy in a big way.