Creating own "entities"

[Alento]

Hey everyone!

I just came across a mind.. I wonder, is it possible to make own entities, I mean, if you, let's say, want to have a bus in your CS? Don't ask why I said bus ^^ But, I mean, if you do like, the bus in, maybe, 3Ds max or something.. Is is possible to get it into my cs then? Or maybe it's another way to get just what I really want in my cs? Hope you got my point ^^

I also wonder if I can change the original wall texture, if I want it so be, like, a brick wall or something?

Just my thoughts.. would be awesome if someone have some answer to then as well ^^

Peace!