Stainless wires, I have driven my +4 all year round for 6 years they are still like new. MWS by the way.
Quite agree with that advice. My 12 years old set of SS wires are like new with no sign of any corrosion. I regularly clean them with a spray on wheel cleaner (Muck Off or similar), using a decoraters long haired, wide paint brush. Takes me less than five minutes per wheel.