First off, let me declare that I like the D4, more than the D3
I had a poke around a D4 S8 at Goodwood a few weeks ago.
It is indeed a lovely place to be, but the one memory I came away with, above all else, was how worn the drivers seat was - now, I don't know how many people how jumped in and out of a show car, probably in the thousands, but the wear (this was a new unregistered car) was noticeable immediately and unacceptable for a near enough £100k car, in my opinion.
I did take some photos, but not taken them off the camera yet, will upload them when I get round to it.