I'm going to rent a car in California for a week soon and was wondering whether to purchase insurance along with the rental. Some sources, eg Should I purchase rental car insurance? What protection does my credit card provide? say I do need it, while a friend of mine claims the agency is by the law obliged to insure you and what you purchase is only additional insurance. I haven't been able to get too much additional information from the place I'm going to rent from. Can anybody give me a more informed answer?
Americans who drive, carry their own insurance that covers them in any car they drive. If you're not American (or live in New York:-)), you're required to carry at least the minimum liability insurance under the California law. Is it enough for you? The liability is yours, in case of an accident, not theirs.
According to this site, in California rental companies are not obliged to provide you the state mandated coverage, and indeed I couldn't find any official reference that such a rule exists (I could only find some claims that it does on various travel forums). This discussion also supports the claim that there's no such obligation.
Credit cards usually provide CDW coverage, not liability insurance.