Ever heard of drop plates?

[Screech16v]

Where does it say that they are 10 mm thick,that one in the pic looks more like 20mm going off the 17mm bolt heads next to it 

[robjackson]

I think, the ones that were in pvw, which are the anodised black ones that pop up on google search are most likely going to be ok for fairly light use and get the thumbs up off me as a really good way to a: relocate the rear wheel in the arch,
and b: take the car down further so the suspension fitted doesn't have to work so hard at big level drops.
if it shows signs of exesive use, take em off and ditch em
the pris & cons could go on for ever