I have used a clear silicon sealant to seal the gap on the inside between the main rim and the inserted section. It is at this joint that the peeling and subsequent corrosion starts - there will be a very small amount of movement between these parts as the wheels turn which causes minute fractures in the lacquer where water can ingress and start the deterioration process. When you wash the car be sure to dry the inner rim of the wheels as water will settle at the lowest point and again start the corrosion process. To date my wheels have stayed corrosion free.