How I replicated an $86 million project in 57 lines of code
Tait Brown

I believe they’ve been doing this kind of thing in the UK for a number of years now, though I may be wrong.

As I understand it, police cars there download a local copy of the database whenever they have a good wifi connection (e.g. at a police station) to ensure a quick and reliable check at all times, and back off to online data when possible. This ensures that basic checks can be carried out, even in remote areas with no mobile data.