Ian Dunt at politics.co.uk:
There are basically three choices for Britain’s customs arrangements. The first is a bog-standard customs union. The second is a customs partnership, otherwise known as the ‘hybrid model’. The third is frictionless trade using technology, otherwise known as ‘maximum facilitation’, shortened to ‘max fac’. You’d be forgiven for giving up now, but stick with it.
The first shows that Brexit is pointless, the second is insane and the third is impossible.