Is this even remotely right?

[Mom of Rick]

What is the name of your state? South Carolina

My son was hit head on by a driver of an 18 wheeler a week ago. The owner of the truck has Canal insurance. The driver was charged with DUI and arrested at the scene.
My son was the 3rd car hit, but recieved the most damage. He drove a 1974 Chevelle that was totaled. The state trooper and the investigator say the sturdiness of this vehicle is what saved his life.
Yesterday, the adjuster called him to say "the car has been totaled-- you can not get a rental-Due to the age of the vehicle the offer is $900 for your settlement".
I assume this is for the vehicle ONLY? Right?
He was not injured badly(thank God) However, he does have an emergency room bill, x-rays, prescriptions, and 4 days of lost wages. I assume the owner's insurance will pay allof this without any trouble Right? It was filed on my son's BCBS the day of the accident.
I guess my question is--- Wwithout significant injury, is my son screwed? Because he will never replace his "family heirloom car" with ANYTHING drivable for $900. So is that it? do? accept this settlement with his med bills and his lost wages paid?What is the name of your state?