They might keep driving, but some infotainment features (or even other features that are tied to subscriptions) might stop working.
Depending on the implementation of these features that could mean the car constantly shows error messages, or the infotainment freezes, or in the worst case the car won’t even start or charge.
Some of these concerns are true for newer cars of traditional manufacturers: what happens when their online services become unavailable?
A typical office keeb is around $15. If you can build this for anywhere close to $150 I’m gonna take 2, please!