chris birkbeck rally school sells the arches, look for their site.
Its about 750 quid for the whole 4 corners (no middle sections and not painted!)
Craigos - it was a normal Ka with the arches, prwoodford owns the ONLY one to roll out of the factory with ford racing parts fitted to it.
A lot of people buy the kit though, and i will be doing the same in the future.