I guess that is one way to chase away UK visitors bringin income into Spain which was hard hit by the pandemic. Not the cleverest thing to be doing at this time especially as many will have already been there for several weeks..I read in this mornings paper that the police in Spain are being quite vigorous in chasing up UK registered cars that are not displaying the new UK identifier. Another aspect I hadn’t been aware of is that from the end of 2022 visitors to Schengen countries will need to possess an ETIAS visa waiver valid for three years. But like the scheme for the US and some other countries ETIAS can be applied for online.