[central_va]

If BMW makes minis in the UK with parts across the supply chain, it makes more sense to shift the British manufacturing bits to the continent

If. Or it may make more sense to pay the duty on the parts and keep the factory open, even IF THEIR IS NOW A DUTY ON PARTS.

To continue with your example: They (BMW) can move the mini cooper plant to the EU if they want but the cars they now export back to the UK WILL have a duty applied to them. OF THAT I CAN ALMOST GUARANTEE. Better to pay duty on a box of wing nuts then THE ENTIRE CAR.

[Cronos]

you don't seem to get it that there duty is not a one time on one part.

An extreme case are some Vauxhall cars that ship back and forth across the channel three times as whole entities. That's not including the cost of the parts moving. This means each move has a tariff added to it.

imagine that - it's not a one cost on one part but multiple costs on multiple parts

[Cronos]

About the mini cooper. Yes, they would move this to the EU, because they sell more there (larger market). Exporting to the UK will mean the prices will be higher, yes, but:

1. The competition will also have the same higher prices so no competitive loss
2. They sell more of those cars in the larger market than in the smaller

It's a no brainer to move the stuff to the larger customs area.

[Cronos]

Hard Brexit will be a disaster economically. It will also mean that the UK will reduce to England+Wales. And they will lose diplomatic power on the world stage. But maybe it will be worth it for them.