Noone wants to have the first headline of "Massive multideath accident involving kindergardeners caused by software glitch" attached to their brand. Particularily not German carmakers who both emphasize how pleaseant and exciting it is to manually drive their vehicles ("Fahrvergnügen", "Vorsprung durch Technik", "Freude am Fahren"), but also use passenger safety as a major selling point.

Disclaimer : i work on one of these car manufacturers IT departement, in close link with the "connected car" team.

The reasons are multiple. 1) building and upgrading a car model take them at least 2 years... in the meantime, they have time to clock the kilometers anyway.

2) They have no idea how to build that type of data "massive" environment. They just don't know. Like all our "connected car" data came onto one single thread acceptor on one single machine. No load balancing, no scaling nothing, until August when the vacations congestion overflooded it. So now we have 4 threads in that single machine. I could ramble on and on on this type of mistakes they do. They just don't know. And this year, they asked the team to reduce their budget. Because it is how the car industry works. After two years to kickoff the project, you have to cut your cost by 5% to 10% every year.

It doesn't fit into the development model of car companies at all. Typically you have a 3-4 year development cycle for cars. Within that period lots of stuff happens, from getting contracts with all the suppliers, developing all the individual parts (often from scratch, if a different supplier than the previous one was chosen), integrating that into the cars and testing on the road.

After that a car is pretty much seen as completed, it will go into the factory and to the customer and probably get minor updates and fixes during the first year. However development already starts for the next model. Data and information from previous cars won't help you that much, since the systems in the new car will often be very different (as I said, most things are developed externally and from different suppliers, reuse is limited).