I got a set of Nylon washers from blk 31 Kelantan road, the hardware shops there.
But I think u may be able to find them at those DIY stores in shopping centres also...
I simply removed the bolts. The sales lady said it was more cosmetic than anything else, to keep the wing from flopping around.
This time, no white aluminum oxide (galvanic corrosion) around the bolts or any sort of rainbow discoloration! Didn't miss the bolts either, and one less component to worry about during the post-trip equipment stripping session