I recently rented a $65000 luxury car and it didn't even have built-in daylight savings adjustment. Owners have to dig into settings and fix it themselves twice a year. Cars are so far behind on basic software it is crazy.
IMHO, the real failure is when devices make it hard to figure out how to change the time.
so the manufacturer gets to choose between making people apply DST changes manually twice a year, which most people understand and are used to doing for various things, or changing over for DST automatically but being wrong sometimes, which most people won't understand and will complain about.
The trouble with all the modern cars that have synchronized clocks is that, well, you've already put in an LTE SIM card, so why not send up some telemetry at the same time? And here we are, with cars that are surveillance devices with four wheels.