My aftermarket alloy wheels that the PO fitted are a mess and had clearly been stored overwinter without having been cleaned. The clearcoat has gone in many places and there is pitting. The spokes are fine and it is just the flat rims that need work with wet and dry. It would be easiest to spin the wheel of course and just hold a pad against it. How safe is it to say, jack up one rear wheel and run the engine in drive?