Quake3World

Hello
im working on an singleplayer mod for quake3
there are some features ive want to include but i dont know how
i hope someone can help
Ive want to add an feature that you can unlock maps and models
in example:you complete the first level of tier1 and after you sucess you unlock the map and the bot model who you defeated for multiplayer mod but you need to complete these singleplayer level to unlock the model and map"
how can i make something like that?
and how can Ive add some little Trailer/video before an singleplayer level

Well, there's something like that in the original Quake: completing one tier will unlock another. Haven't had a look on that myself, but it's something you could start with.