I have new Vee2 purchased last September. I live in south of Portugal with 300 sunny days a year, temperture never bellow 15ÂșC in winter. Bike is parked in my completely dry garage. Few months ago I noticed all black bolts - fairing, front mudguard, side plastics, etc. were all getting white. Tried to clean them but noticed it was oxidation. Since then, I changed all of them and lost the count of how many they were. Had to order new ones from eBay, stainless. And all the bolts on Vee2 are "collar bolts", and those in stainless steel are very, very expensive. I had to purchase non-collar bolts, the same size as OEM ones for each part and then separately the collars, so I wouldn't ruin the plastic parts on my new bike.
I did said something about this to my dealer and his comment was: "Suzuki bolts are stainless... a little bit..." That explained everything.