I work for an auto supplier that supplies vehicle communication software, so I can confirm first hand that some 2018 vehicles currently on sale already have these firewalls:
http://www.bosch-mobility-solutions.com/en/products-and-serv...
(happily keeping my late 90's car running, although my most recent car literally has gone 100k miles with _NOTHING_ but oil, tires and brake pads). Its now at its first service interval and I'm wondering if I should just trade it in before anything breaks.
That is a potential problem, especially for "hacker" type suppliers (offering performance components for example). That said, the manufacturer I work with sells their diagnostic tool to the aftermarket, so at least aftermarket garages can get access for repairs.
Also, one thing I really want to know is what happens to all the data from frontal collision warning systems, rear view cameras, etc.
I wish there was in-depth information about this what manufacturers do. I found an article but it is light on datails.[1]
[1]https://www.washingtonpost.com/news/innovations/wp/2018/01/1...
On a similar note...
Eventually some genius consultant for an automaker will earn a handsome bonus for introducing the idea of a secure car: one with no network or wireless functionality whatsoever.