If the car behind yours was pushed into your car by a third car that hit it from behind do you file a claim against the car that hit yours or the one that hit him and was cited for causing the acciden?
If you have comprehensive/collision, file with your insurance
company and let them fight it out. If you only have liability, file
against both and let them fight it out. If you get any hassle at
all, talk to a lawyer. Sometimes a letter from a lawyer will be
enough to get the insurance company to treat you seriously. If
injuries were involved you can probably contact the state to find
out how to proceed.