Using the models right out of the game is absolutely definately a no no. If you made your own version from scratch it would probably be a different matter. Then it would be basically a work of parody or fan art... Not strictly legal, but more likely tolerated. Go ask the guys who made the Generations mod for Quake 2. they got got their (quite Fun) mode wiped out for doing just that, and it takes a lot to get Id in a snit. It was a fun mod. (still is on my LAN... LOL.)