Will it ever be possible to cut or slice parts?

As if you had a saw and could make arbitrary cuts, even slicing parts apart. I've always wanted to remove the dry van trailer's underride crash bar.

 

Making arbitrary cuts at will would be virtually impossible, as it would require a ridiculously high density jbeam, however "tearing" of jbeam parts can be simulated (e.g having a car split in two in a high speed crash) at predetermined points just fine, though the way the mesh tears needs work (currently results of parts of the mesh disappearing)