I was thinking about breakable nodes in all cars, something like: if force applied to node x (applied to every node of the car except glass) exceeds force y then node x splits in two. It would be cool for impacts that may result in a splitting of the car, like a T-Series with a snow plow against the side of a small car.
There is a mod for a split able Ibishu Covet but I am not sure whether it is supported in the latest version.