Screws for an Auto DS Side Skirt?

Sorry if this has been asked before, I have had a good look but not found the answer I’m looking for.

My Auto DS LE side skirts didn’t come with any attaching screws and it’s recommended to use 2 self tappers on each side at each end.

I believe I’d be best with stainless steel self tapping screws, but can anyone that’s done this before advise me of a head size & thread length please?

I’d be really grateful for any help

Just use sikaflex or tigerseal or whatever, no need for screws at all. I'd drill a drainage hole at each end of the underside though.

Many thanks for the reply Graham

I did. Test fit, but there seems to be a fair gap to take up. I thought maybe by using screws each end, it would take up the space.