Robin, ah gotcha. I don’t think I’ve ever done such a detailed deformation. I usually have that set up with simple geometry and keyframes. It would be interesting to try though…
With PDI I believe I would have to parent a deformation object to the shard that would hit the car. I’d have to double check though, it’s been a while.
Haven’t done deformation in houdini at all. I’ll get back to you on that 
Mathes, I haven’t tried it. I’m just starting to learn Houdini. For PDI I set up a script that did: Bake keys on shard, Parent bone to shard, bake keys on bone, remove keys on shard, Parent shard to bone, Parent bone to main rig. Since this is pretty straight forward I can imagine it would be possible to set up procedurally in Houdini. If not, you could always script it there as well. However, I don’t know what export formats and so on are available in Houdini so I would probably leave that whole thing to a TA.