Yeah they're a good price. The original owner has now retired but his daughter now runs the place and they've done great work at not only repairing but powder coating wheels in the past.
http://www.wheelrefurbishing.co.uk/
They're not down Chiswick way but I've used them before on old cars and have been very good. It's not THAT far out of your way maybe?
If you're in the SE these guys seem good - a friend has used them before (not for a Zed though):
http://www.hydro-graffix.co.uk/index.html
Decent price too in my opinion.
http://www.ebay.co.uk/itm/Mines-Carbon-Front-Splitter-Front-Lip-for-Nissan-350z-2007-2009-FACELIFT-/251334380942?pt=UK_CarsParts_Vehicles_CarParts_SM&hash=item3a84b24d8e
Pure sex
I think the reason it's cheaper to park on the street is that potentially a thief won't know where you live to steal your keys. But in your example it does seem rather daft!