See https://imgur.com/NggmdMf
It looks like rust? Does anyone know what's causing that and how to remove it?
Doesn't look like enough to worry about. You could probably remove it with a scouring pad or steel wool.
That area is not air tight, there is no gasket, so moisture could get in there and cause the corrosion you are seeing. Make sure the Suzuki "sticker" is well attached and you bolt the cover down to spec.
Thanks, that makes sense.