Physics: Rigidbodies sticking together and softbodies not retaining shape I am trying to simulate a car crash in Blender 2.8, but during the simulation, several errors occur. The meshes seem to stick to each other, most likely the rigid bodies, and they will continue to follow each other for the remainder of the animation. The cars then phase into the ground after collision, jittering the entire time.
There are also issue with the softbodies, that is that they will not retain their initial &quot;crunched&quot; shape upon collision despite having a high plastic setting (100). I have tried to solve this issue by keying the stiffness to the moment before impact, but for some reason the softbodies still collapse before they even hit.
I have set up the simulation using the following method:

I have a deformed body which has no dynamics of any kind, which is broken up into pieces like the windshield and tires.
I then put that deformed mesh under a rigid body which is used to collide with the floor and the other car.
I then parent a soft body under the rigid body and use that and a mesh deformer to alter the deformed base, and I apply colliders to both cars and the floor.
I then toggle the &quot;animated&quot; function of the rigid bodies to switch from a keyed movement to pure dynamics.

An alternative to this current method would be using shape keys and sculpting the damage of the collision, which would remove the need for softbodies, but I want this simulation to be almost entirely driven by dynamics so that I can use it with any vehicle.
Attached in this link is the Blender file:
https://www.dropbox.com/s/dyl0tvlgpmzuzyk/CrashTest4.blend?dl=0
So, I found a solution to the rigidbodies falling through the floor, though they still stick to each other (collision margins set to .1).
I made a new rigidbody with a much simpler cube with a few extra edge loops and increased the mass to 50, and the new simulation does not break into the environment. I am however still having issues with softbodies and the cars still return to base shape after impact.
Here is the link to the updated file
https://www.dropbox.com/s/qnsqfjojrw2star/CrashTest4.blend?dl=0