Depends on how quickly they get on a boat after reaching Emden and whether there's a transporter available once they arrive over here. It's a bit of a lottery to be honest but seems to be 2-4 weeks generally.
I do know that some of the week 20ers are picking their cars up this week though so that's just about 2 weeks after build week.
Mine was build week 21 (which was last week) and I know its left the factory but that's all. I'm hoping to hear something next week, although the bank holiday may put it back a few days.
Hope that helps a bit.