The holes on the inner wings can be filled using a variety of material. I used grommets on the small ones, a mixture of heat resistant matting , some was self adhesive from Agriemach for the medium ones, and aluminium sheet for the big ones. In some cases where the panel is flat, I sandwiched two aluminium discs - one either side of the panel, with double sided tape cut to the size of the hole.
This one was to reduce the size of the hole where the exhaust passes through:
Onto which I fitted a heat shield for the master cylinder reservoir:
