United State's auto insurance companies typically only offer policy terms of 6 or 12 months, so it will be difficult through a normal auto insurance company to obtain insurance to drive into the US for just a couple of days or weeks. So through our online quoting system we cannot offer you a short term (weekly) US car insurance policy.
There are specialty car insurance providers that would offer you such a short period of coverage.
Auto insurance companies that specialize in "border insurance" are what you need to find for your situation. This type of insurance company allows US drivers to drive into Mexico with the required Mexican insurance and reversely there is also coverage for Mexican vehicles that are driving into the US with some insurance providers. You first though may want to see if your Mexican car insurance company can provide you with coverage for the short time you plan to travel to California with your vehicle.
If you insurance carrier in Mexico cannot provide you with the insurance you need for the US then shop around with those companies that specialize in border car insurance.
We have an online partner that is a Mexican car insurance provider which may be able to help you find temporary insurance between Mexico and the US. Mexico insurance online is being offered at CarInsurance.com through International Insurance Group, Inc. (IIG) in conjunction with five of Mexico's largest and most respected insurers, GNP (A.M. Best rating A), ACE Seguros, GE, Zurich Mexico, and ANA Seguros. They offer an online Mexico Tourist Auto policy.
The IIG site offers on it short term Mexican insurance but also has on it a link for insurance for US travel from Mexico or what they also refer to as "northbound insurance." Here you can get a quote for US trip or travel insurance.
If you have US registered cars that remain in California or elsewhere in the United States you can get a quote here for discount auto insurance.