BeamNG is the more precise soft-body simulation software/engine that we can try for free actually (i guess). The damage on vehicle structure and parts is incredible:
Unfortunately i don't think that we will have something like this in GTA V, mainly because GTA V will be released in September of this year and nobody said anything about more real car damage physics or something like that.
Maybe in a next future we can have a GTA style game with this kind of reality for cars, this would be awesome.
You can try the Free Tech Demo of BeamNG to have the feeling of a more real car damage, enter this site and click in TechDemo or just click here. This version goes with one map only for demonstration with some ramps and obstacles but you can use the World editor (F11) to edit the world and make an more dangerous ambient ^^
Also you can buy the full version that is constantly being updated with new cars, maps and improvements here, it's only $15 and you can have a lot of fun kidding with the car physics in cool maps and have access to all features in the World editor mode. The limit is your imagination (and computer processing capacity lol):