Future Changes to Model

For my model I want to add some kind of floating glowing orbs or squares. These will be similar to some kind of futuristic car or space ship. I would like to make these moving back and fourth but also to move out of the players way as they move through the model. This will mean that the video is not hindered by no clipping through what is perceived as a solid object. I could also try make some building extras that will fall or move when the player gets to them. it will feel like the city is falling apart. These should be easy to make as I can use the scale tool in Cry Engine to fit each piece to a corresponding building.