I saw the poor thing dragging itself across a parking lot at work. It was so emaciated that it didn't resist when I just picked it up. I managed to get it into a box, get it food and water that it was too weak/anxious to consume, and called the local wildlife rescue to hopefully get it some help. Its condition was so poor that I doubt it would have survived the night so I'm not optimistic about its recovery. Fuck cars.
If it's back legs are permanently damaged I doubt it'd survive the wild. I hope you can find a good home. Maybe make a wheeled harness for the back legs?