I experienced something while testing this with @Manason: I think this currently works if you hit another car directly in the front or rear bumper.
It has to be almost perfectly head-on, and if the vehicle has a rambar (like trophytruck) or other add-on/part it seems to require deformation of the model to a certain level to trigger, maybe because of the rambar/props the hitbox of the vehicle is protected and this doesn’t trigger even when hitting peds when the native is set like:
SetFlyThroughWindscreenParams(0.0, 0.0, 0.0, 0.0)