And I believe the automotive engineers are much happier to keep using old proven parts if there is no reason to replace those. Unlike software, where every new thing will have to be done with something different.

Exactly even those will have same the chips as the regular cars. Just because you have big expensive chip and stuff for self-driving doesn't mean the other systems doesn't use standard off-the-shelve solutions like ABS and so on and on.

People just think the CPU or GPU, but what about power supply, peripherals, busses? All sorts of auxiliary stuff...