Mercedes does that. If you buy their EQC you can use any charging point in the UK and start charging through the Mercedes ME app, it will be billed to Mercedes and then they send you an invoice later. Apparently it works really well but obviously it requires Mercedes to maintain hundreds of different contracts with all these companies

Do you have an account with every gas station that you use? Grocery store? Restaurant? There's some tech bias to this line of thinking.

No, but you pay for those by tapping a card on the pump or going into the shop. The suggestion here was some sort of magic communication between the car and charger, which would require either the car to be a payment instrument itself (obvious security issues) or for either the car vendor or car owner to have contracts with a whole bunch of providers.

I don't see the obvious problems with the car paying. It can do exactly what google and apple pay does. Issue a one use token for payment to the charging system which is ultimately redeemed with a credit card purchase/money transfer. The only needed system is for either car manufacturers to setup their payment systems, or for them to rely on some 3rd party to provide the same system. There's already an android auto and apple auto so I'd imagine google or apple would both leap at the opportunity to handle payment for them.

The only way with obvious problems, to me, is a system that requires you to pull out a credit card. That is wide open for card skimmers.