Posted 02 October 2013 - 02:26 PM
From what I understand, if tread can be seen protruding from above, then it's illegal, or at least that's the method that plod seem to use to ascertain legal anyway. I've seen many archless cars at shows, but I've yet to see one with the 8.4" brake setup running anything larger than standard 3.5" steel rims, that could be deemed legal using that method.
Of course it's all dependent upon the offset of the particular wheels in question, and if your rims had a big enough +ve offset to tuck it all under the car, then you could no doubt get away with it, but then surely you'd also struggle to get 5" rims to actually fit under there enough, without scrubbing against the dampers or rear radius arms?