Legal Question in Insurance Law in California

You cannot sue someone else's insurance company. The California Supreme Court ruled all the way back in the 80s that an insurance company only owes anything to its insured. They may pay on behalf of the insured to the parties injured by the insured, but the duty to pay or not pay is only owed to the insured.

What you need to do is contact the insurance company for the person at fault and tell them you are making a claim against their insured. Because they have a duty to indemnify or defend their insured, they will most likely just adjust your claim and compensate you. If the refuse, however, your next step is to sue the individual in small claims court (if the damage is under $10,000) or limited jurisdiction superior court (damages above $10,000 and less than $25,000). That will trigger a duty of the insurance company to the other driver to deal with the claim.

And just by the way, you have a really lousy insurance company if they will not just pass on your claim to the at-fault person's insurance company, pay you and collect from the other insurance company.