Earlier quoted context omitted.
Most of the stuff in a car could run on a 6502. The rest will run on something akin to the NXP i.MX8. Not at all cutting edge, but more than sufficient. It is more than fast enough to process input from sensors and it has hardware support for video.
eh, modern ECUs, accident compute, etc are doing timing and tuning calculations in real time such that you need something a little more adequate. A 40mhz PowerPC CPU with an FPU, for example. Aside from mandatory ADAS, most cars can definitely get away with "90s tech" but probably not "80s tech"
The ECU obviously needs more compute power. That said 6502 was an over exaggeration.