If you need everything, then you'll need to use "fulfilment of a contract" as the basis, and in that case, you probably need to make your ToS pretty tight too.
For the users that refuse this consent, can I prevent them from accessing the self-driving feature of the car? If not, how would the company deal with the free-rider problem - nobody opts in because they want their privacy but they also want the feature?
AI and ML have to be careful [0], as you need to be explicit about the data's use and impact on the end-user. The most given example for this is ML algos that determine eligibility for financial products, but we could probably twist that Tesla example to fit a similar to be "my data is used to inform an algo that determines what the car does in a dangerous situation", so you might have to abide by rights to explanation and data editing.
[0] https://ico.org.uk/for-organisations/guide-to-the-general-da...