Well, the obvious issue you're missing here is the fact that the steering wheel is on the right/wrong(heh) side, hugely limiting the potential for exporting your second hand cars elsewhere. Even then, I do know about a few successful businesses, where people have been exporting cars from UK to Poland, moving the steering wheel to the other side, and yet still making money in the process, the value of second hand cars is so much greater there(in the UK a car that is 6+ years old is basically ancient, in Poland that's still considered "nearly new").
+1
Your right, that was a glaring oversight and does also play a big factor.
I was somewhat intrigued by the use of the term mainland, but it certainly has some debate behind it: https://english.stackexchange.com/questions/3652/how-to-refe...
Yes second hand cars in the UK are cheaper, factors being that there has been a consumer rise for a while, seeing more second hand cars. This with the island effect makes for dispersal of those second hand goods more curtailed and for example you may be able to get cheaper cars in Germany second hand if the geography curtailed those easily shifting to nearby countries who have had less of a consumer drive.
Which is why my friend in Bulgaria will buy a second hand car in the UK, drive it back, sell it for twice what he paid for it. Then in Bulgaria Walnut wood is about 1/5th of the price of what it demands in the UK. But most opportunities in life are going the extra mile.
Yes UK is still technically an EU member during the transition period. How exporting/importing of cars pans out, well as long as the we don't end up with trade loop-holes - then I'll be happy and by that. Say EU has import tax of 30% on UK cars, new or second hand. Yet no such taxes for imports from say canada. Then the UK has no tax import on cars from UK to canada, so would be possible to export to Europe, via Canada to skirt such import taxes. That kinda thing worries me as environmentally, not good. But could happen.
All I do know though is that the current trade negotiations seem like a Monty Python playbook:- https://www.youtube.com/watch?v=CK0cUv3ba-o