Watch what you sign (Paper work) and watch their check they give you for the car. Some insurance companies put a waiver that states that you agree that the settlement is FINAL by signing the check (small print in the signature block on the back of the check). Definately keep in contact with your insurance company with what is going on and what you are doing. THEY INSURE YOU from loss and will usually battle the other insurance company for you, so they dont get stuck with any liability. If they dont seem to be cooperating, speak with a lawyer.
Zig