"Dont trust google" imo is the wrong response here. We are at the mercy of our institutions, and if they are failing us we need mechanisms to keep them in check.
Cars are under quite strict laws that software isn't. And there is only a small number of car vendors, while there are several orders of magnitude more extension vendors. Also a car vendor is a big company with many audits and controls, an extension "vendor" could just be some guy in his garage office, who just sold it to scammers, even for popular extensions.
And I still wouldn't trust a modern car using subscriptions and code updated.
The threat model is really very different.
Straw man. The argument is that by installing random extensions you trust anonymous developers *because* Google doesn't audit. I'll cite the parent to spare you the effort of reading it again:
> The Chrome Web Store is basically unregulated and Google doesn't care.
Yes, I trust the contents of the medicine I buy at the drug store more than I trust the drug dealer on the corner. That's why they hand out test kits for free at raves.