> Even on older cars, service techs can typically manually push firmware updates
Older cars have no concept of such updates.
Happy with my 70s and 80s and early 90s cars.
You can adjust the ECU for these 80s and 90s cars and “flash” them like anything else. There’s just a lot less settings! Not sure about the 70s but I’m sure some resto-mods also allow for this.
Actually almost any fuel injected vehicle can accept flash updates through the port to at least the ECU and PCM, frequently the BCU is also write enabled.