Doesnt anyone look beyond one car in front of them? Keeping a safe distance is one thing, but if the guy two cars up in front of you jams on his brakes and the guy directly in front of you is day dreaming, your butt is toast and are liable for the damage you caused. Now, for the lawsuit, forward it to your insurance co. That's why you pay them, they will either deny the claim or negociate it. Since there seems to be no factual proof the the accident aside from damage, they might just dent it.