Earlier quoted context omitted.
Maybe worth looking into how Amazon Kindle solved it years ago? They offered free GSM/3G? access to the internet, something like 150MB/monthly, unlimited access to Wikipedia, in so many countries, basically everywhere.
And car companies presumably have global agreements e.g. I can drive my car across Europe and have all the navigation related stuff continue to work. But easier for Amazon or big car company to broker such an agreement. I think the question is how would Joe Public get something like this.
Well, since a year or two EU-wide free roaming is a thing.