Well, it gets closer...my car was in transit this morning, and shows as in the UK now
It says it'll take around 7 days to get to the dealer, which is fine by me as between that and the preparation, it means they shouldn't have to hold onto it for very long to register in on 2nd September or after.
Edit: I was build week 32, so on the assumption that I collect it 1st week of September, that makes it a delivery time of 5 weeks including the build week, so bang in the middle of the 4 - 6 week advised estimate.