You forgot to mention that the Krauts are mixed up in this dispute too.
They charge British coach operators VAT to use their roads and their
police have powers to seize coaches not carrying a German VAT
registration certificate.

The office that's supposed to deal with the issue of these certificates
(Finanzamt Hanover-Nord) routinely ignores requests from British coach
operators for VAT registration forms - even if they are written in
German!

Perhaps the Krauts should sort that out before crying over the
Congestion charge, then they might earn a bit of tourist income in
Sterling that would enable them to cough up to Ken.