It depends tbh as airboxs do come with screws fixed in place sometimes so maybe part of the larger plastic trim part, so it would be checked per chassis tbh, just give audi parts a ring & ask or pop into a dealers part desk.
TBH mate, just go to diy store with another if it has more than one & match the thread etc to that, much simpler.
Yes they will, I bought a pack of ten when I needed the exact same screws. It'll be about 20p
I disagree with the above regarding going to local diy store and getting one that just fits. The previous owner of my car did just this for the same screw and it was cheap monkey metal screw that rusted and took the slam panel with it. Besides that if it was from B&Q it probably cost more than a Audi screw!