So many replies to this without a single person mentioning that cars are extremely dangerous and kill lots of people every year. However, over the past 40 years cars have gotten much safer and kill far fewer people. A lot of these safety improvements are structural, but also a lot of them are due to the fancy onboard computers which are doing traction control and blind spot monitoring and deciding which airbags to deploy and emergency braking and on and on.

When a person driving a automobile runs through a crosswalk and hits and kills an innocent child crossing the street with their bike, an accident that could and should have been avoided by automatic emergency braking, a great cost has been inflicting on society as a whole so a person could save $500 on their car.

The price of each individual car needs to be calibrated with the price to society of all the bad things cars do. And this isn't a hypothetical situation where cars might kills tens of thousands of drivers and thousands of pedestrians every year --- they already do. Mandating safer cars, even if this will increase manufacturing costs and bring up all these new data privacy issues, has a huge positive impact on the rest of the people that happen to share the world with those cars.