They may do round your way Harry, but round here but I’ve never seen them in anything other than a foreign registered van. Of course you cannot check the tax, mot insurance etc on a foreign vehicle.
Mottie has taught them how to avoid detection.
Except he's talking nonsense, as usual. But he is a self-confessed and proven liar.
When these vehicles enter UK, they are recorded at the ferry entry point, at least on CCTV. They must be registered with the carrier, i.e. the ferry company.
So the police could easily check and know when these vehicles entered the UK. Even if they are totally legal, they are only allowed to remain in the UK for 6 months.
Additionally, in the EU there is a process that allows police to share the registered owner, and other details of foreign registered vehicles.
It is this process that London is illegally using to obtain the registered driver details of foreign registered vehicles that don't pay the London Congestion charge etc. (It's not seen as a criminal offence, so it's not covered by the EU process)
UK can still use this process, even post Brexit.
Then these vehicles would be crushed, and the drivers/keepers prosecuted.
So the processes are in place for the police to use, if they wanted, if they had the resources.
Moreover, the entry and exit of individuals are also recorded at border points. So the police and border officials could easily check the dates of entry of those found to be driving/operating these vehicles, and deal with them as illegal immigrants.
Unless this is all a figment of Mottie's and Harry's racist imagination, and these vehicles don't exist at all.
It's just the typical culprits making up false allegations to inflame community tensions.
And we see the results of such disinformation.