Who do I sue the Manufacturer or the dealer?

I had a hit and run a year ago the guy completely totaled my car, it was a front end collision i had my seat belt on but my seat belt never locked nor did my airbag come out. I was left not only with the burn from the seat belt (which was okay) but the imprint of the steering wheel and bruises for months. I was wondering who I would sue if I could sue and how I would go about it?