I guess given the dealers are franchise, they all have slightly different ways of approaching the acquisition of vehicles. The other thing I've learnt is that Audi AG and Audi UK buy/sell the vehicle from each other and this is part of the process we don't see. Albeit back office and more often than not without issue, is another link in the chain that affects getting vehicles out of ports.
In respect of it being detailed professionally, you acknowledge the exact reasons for having it detailed - a third party detailer is afforded more time and therefore able to rectify any issues that may be present. For the dealership not to get a chance to introduce any further issue will only present the car in a better position to the chap who'll bring it 'up to standard'. Given the detailer is only having the car for three days, it's not going to be the end of the world. I've waited near on 7 months for the car and I intend on owning it for 6-8 years, so in the grand scheme of things, no biggie. Also, I suspect I'll spend the best part of a day go through all the infotainment and technology options.
Dealers love to give cars to customers, of course they do - it's how they realise their targets I suspect