It could be possible to add an option to Turn Off the 'Instability Detected'... it's fine as a protection, but it should be optional if you don't want it. I installed a mod to make the cars more resistant, but when there are very hard impacts, the game pauses due to 'Instability Detected,' and it ruins my recordings for my YouTube!
I enjoy watching cars get wrecked, but when it comes to extreme off-road racing, even the slightest hit with a rock can knock the wheels off, making the car unusable. Or with big jumps, the cars end up totally ruined, and I can’t keep going in any extreme race. In this case, I’d prefer that they deform just enough so I can keep racing in extreme conditions.
It's not possible to just stop deformation like that. Maybe there are some mods for stronger suspensions that you could try.