OP, it sucks to say this, but you're going to have to put in time to negotiate and fight with the insurance company. There are a lot of good ideas above to assess the value of your car. Find some "for sale" examples, NADA, start putting together a file that shows the true "street" value of the car. Heck, if the insurance company doesn't offer you anything closer to its real value, tell them...NO...DEMAND for them to have it fixed. It will cost them more to fix it than it's real street value. Bottom line: Put up a fight.
I worked in rental years ago. I can't tell you how many times a customer came in complaining about the insurance co pulling the same BS you are going through. In all fairness to the insurance co adjusters, their job is to minimize the losses. We all have jobs to do.
BTW...how's your neck and back? (don't answer this).