So set out to roll my arches so I can get ultimate wideness at the rear! Jacked it up and took the wheels off, first job was to remove as much dirt and build up from the arch as possible with a screw driver so I didn't cause any damage to the arch once if started rolling. Then cracked out the heat gun, hammer, rag and a bit of courage :S
My tool! I wrapped masking tape around it so's not to damage the paint.
Heating the area to make sure I don't crack the paint when bending the the lip up.
First bit on the first side.
First bit done on the second side. I rolled them progressively so did it in two stages, roughly 45 degrees then did it again to as flat as I could get it.
Example of it fully rolled (or as flat as I could get it)
I also stupidly cracked some paint from being a bit eager and going back to a bit where the paint was no longer hot, so I sealed it up with some sealant as you can see on the arch in this pic.
Thanks for looking guys, and maybe it'll give some other guys a bit more courage to have a go at some DIY
Dan