Redesign and replace current damaged vehicles
This idea is probably worth leaving until #726 has been complete, as then there will be a number newly created futuristic vehicle meshes to create damaged vehicles from. It would be worth considering and allowing for a number of different means of vehicle destruction. Be it through fire, being riddled with bullets, just panel damage etc, and there can be varying degrees of the seriousness and extent of the damage.
This will really help in making the levels come alive, and be able to tell little stories to the player about what has happened or is currently happening in specific areas etc.