I have not had problems with my +4 but I have with my camper van. I live by the sea in Cornwall, so have salt in the air and the van is out all the time. It is on its third set of front discs. The backs do not suffer as they are protected by the bodywork. I now use wheel covers that you see on caravans. It protects both wheel and tyre and my discs are like new. They were about £15 each on ebay, and are secured to the wheel by elastic over the back of the wheel.
