hub spacers would be the best for the rear as the hub is spaced out not just the wheel.front would need wheel spacer. iv rolled the lips back on my track focus on the front only so far.the arch liner starts flapping though as its got no support when the lip is rolled. as for arch extentions nevsrevs has done his but to do it you can never go back to standard as you would have to chop the arches away or cut and bend.well you could go back to standard but the repair bill would right the car off. dont lower more than 25mm either has it will mess up the front lower arm angle and ruin handling.