I spent 2200.00 on chrome rims for my journey. I live in the northwest where they put salt on roads in winter, also I live next to the beach. Mine did this the first winter. Its caused by salt and chemicals. I was told I should have gotten poliched aluminum as it will not corrode. Sure wish someone had told me that before I purchased. Now 3yrs later they aren't corroding on the outside parts, but in the inbetweens of the spokes, and gets worse each year. Next time I will get polished aluminum. But will wait til I get a newer Journey as the phased out 16 inch wheels and cannot find my size anymore.