In Paris in December, I sat with a journalist friend in a café on the Boulevard Auguste-Blanqui and listened to him explain to me why a no-deal Brexit would be a catastrophe for Britain. It had to do with an article his newspaper had published about the Mini. You might think they were typically British cars, he said, but the plant where they were made in Cowley belonged to BMW! The steering wheels were assembled in Romania! The tail lights came from Poland!

So? I asked.