The UK has lots of new cars (plenty of cheap financing around for lease, PCP and HP deals), and there is a low-level epidemic of thefts of vehicles that end up in shipping containers and heading out of the country within hours. [0]
Car insurance is also so high in the UK at background levels that if you end up owning a highly desirable and very easy to steal car (the Range Rover a few years ago, for example), the costs being added to price in the risk of your car ending up in a container heading to the Middle East don't seem - as a percentage - particularly high.
The fact UK has great shipping throughput to the Middle East, Africa, and so on, is both a boon economically, but also it makes great cover for all sorts of shenanigans.
[0] https://www.containerlift.co.uk/cracking-the-code-uk-police-...