Apart from the legality issue, I'd be surprised if it handled at all like that though, your steering geometry is going to be all to cock. Your wheel bearings may pack in quite quick too as the load won't be 'central' on them like with the standard wheels.
the wheels can stick out from the arch up to or equal to 2 inches. They also must have full clearence on left to right stearing, and spinning the wheel whilst jacked up. (according to the book)
well they easily spin when jacked up and dont foul any of the bodywork (except for the back under heavy loads or huge bumps taken fast
as for hubs... ******** to that... both rear ones are gone anyway...
hmmm.. 2 inches you say? but will the police go by those rules aswell? i dont really care about producers, but on the spot fines is what im worried about!
anwyay, i have plans for my arches, custom jobbie that i think im gonna have a go at myself. will basicly just make the arches flare over wheels but wont actually make the arches any wider