Apple should buy one of the local EV companies like Lucid or Rivian, it would save them years of R&D on the hardware, give them valuable automotive guidance on the software and how things work in the car world. Lucid's software R&D is run by many ex-Apple people.
Also, I don't think self-driving is a must-have feature and I speak as the driver of a Tesla with full-self-driving. It's just not that useful. Traffic-aware safety features are more valuable and easier to achieve.