They literally can't sell cars any more in Sweden, on account of the postal service having a sympathy strike and no longer delivering registration plates to them. Using the postal service is the only legal means of obtaining registration plates, and without them it's not permitted to sell a car.
How does that work? Do the postal workers see the return address of (the local equivalent of) the DMV and refuse to deliver if they see a Tesla in the driveway? If not, how do they not block other brands?
They have the public IP and a timestamp, which lines up with the ISP DHCP logs.
That said, at least for several major carriers in the US, your public IP changes very rarely. Like months or years with the same IP.