Modded Challenges

Ok so i have been making some basic but nice weapon mods and backgrounds, and am wondering if my mods will carry over automatically in the challenge DL or will the person playing my challenge need the mod files too?

the person playing the challenge will be unable to play the challenge unless they have the mods. the game crashes if they do not have the mods.

like many games this game needs the same thing for the map as for the map IT NEEDS TO DOWNLAOD AUTOMATICLLY like so many games that dont have it they need it