Vehicles from other countries including Canada are less likely to meet U.S. specifications. Vehicles that were not built to meet U.S. specifications must be imported as gray-market vehicles. This can be extremely expensive and time consuming. If you are considering importing a foreign vehicle, you should review what the Department of Homeland Security, Customs and Border Protection (CBP) has to say on this subject, as CBP controls what vehicles may be brought into the United States.
Your intended vehicle must clear customs before it can be registered in any state, including California. The costs for a laboratory to modify and certify the emissions and safety equipment on a gray-market vehicle are considerable. You may wish to contact the California Air Resources Board to learn whether the specific vehicle you intend on importing will conform to California emissions regulations. The ARB number to call is (800)242-4450.