Javadude
Rolling Arches is when your is lowered and have alloys fitted on, aince the alloys are wider and a various sizes sometines you to get the inner lip of the rear wheel arch rolled as in folded in, this requires alot of skill as sometimes the outside paint on the wings cracks so it's got to be professionaly done, using a very expensive piece of machinary..
Hope it helps mate... will be posting piccies shortly, am at work so will be going out in abit, please be patiant.. :o :o