What you should know: 1. How to download and use modeling programs 2. How to use the Mission editor 3. How to speak C++ Scripting language As far as the models go, I have no idea. I just use the trucks from the stock EM3 In the strategy first folder there should be a manual to the mission editor and that may give you an idea of what its like The toughest part is writting a mission script which controls the car accidents and adds objectives and pretty much runs the mission and without it, the mission won't run. Answer to 1: Yes, you need a modeling program and I think its Z-modeler but the mission editor is installed with the game. Answer to 2: A floor is what makes up the grass, dirt, stains, roads, etc. You need to make it in a program too. Answer to 3: Just build the model and use the script files in the game to add the vehicle, and the equipment and people who can ride in it. I know I'm not clear but that is as clear as it gets! Most people learn by looking at other maps and mods. Good luck!