Just purchased a pre-registered S5 Trophy LR from Stoneacre Derby, cost £23,700, 55 miles on the clock.
A very straightforward process, all completed in one visit (because I live nearly 60 miles from the dealer).
Excellent assistance from Dan. So far, everything has been great and so, as of now, would thoroughly recommend them.
Because of the distance involved I will not be using them for service - they were perfectly happy about this, understandably perhaps - but will use a more local dealer, with whom I took a test drive but who had no cars available to buy at anything close to the Stoneacre price.