Insurance finally admitted fault

It’s been a year of back and forth with the insurance company. Story: about 11 months ago I was hit by a suv that didn’t halt at the stop sign and I only had liability insurance. After the accident my insurance (progressive) noted that since I only had liability they can’t represent me in any way against the other insurance (State Farm) or provide recommendations on next steps. At first State Farm seemed very friendly and they heard both my side and their customers side of the story. After 2 weeks of their investigation they noted that their customer said I had my blinker on to turn and that they found me 50% responsible, (which is not true) and they basically said they had to side with their customer. I ended getting a lawyer and after 10 months of back and forth they are now taking 90% liability. My question is how are they going to calculate the value of my car since 1 year ago the auto market was a lot higher and also I can’t find similar cars for sale in my state. (Same trim / miles)