Many businesses in South Bay offer Mexican car insurance on a short-term, prepaid basis. Most large car rental companies in San Diego do permit their vehicles to be taken across the border but generally require a hefty fee, sometimes costing more than the rental, for Mexican auto insurance. Visitors to the region should note that automobile insurance does not travel across the international border. Vehicles registered in Mexico may also require separate insurance for use in the United States. In California Automobile insurance is required by the State.