I have just been enquiring for my new car. Apparently the lower part will arrive on the car as standard (on the V12V) and the dealer will arrange for the full rear arch coverage. The dealer price is £250 I think - may be available for less elsewhere.
I would imagine somewhere like Paintshield (ask for Tom) would be worth talking to.
I would, however, simply opt for the front mudguards. Don't think I have a chip on my rears. Car has had the front guards fitted from new following reading up on here.
