Hi All - quick update: I bought the car!
Checked it out very thoroughly. Wheels are legit, and all the paper work was in order. Very pleased with it.
It drives superb. The Santiago alloys look very good. There is a slight kerbing on one of them and a minor scratch on the lower skirting; does any know any good mobile alloy wheel and dent repairers in London?
Must say, the car is impressive. The grey looks superb, real head tuner. The Tyre Pressures were low, but other than that, the car was in perfect order. Look out for lots more questions, as I'm sure I'll have many things to ask. Wading through the instruction manuals is not as fun as talking to fellow owners.
Thanks to everyone for all their valid contributions - very helpful.