State laws vary so you will need to find out from your state's insurance regulatory body if the settlement your insurance company is offering is considered reasonable and allowable. In most situations if a car has been in a severe accident previously it lowers the value of the vehicle. Loss of value or diminished value is basically the difference of what your car was worth pre-crash and then post-crash. This vehicle of yours was previously found to be a "total loss" plus now had a second severe crash so the car will be worth less.

In many states, if a car was found to be a total loss previously then the title would have been changed to a salvage or rebuilt title. You say you have a clean title though so mention this to the insurance department when you contact them. You have the right to disagree with the insurance company's assessed value of the car so beyond finding other 2001 Camaros in comparable condition and continuing to negotiate on the settlement amount you might have to consider getting legal counsel.