...for those NOB driving down from British Columbia, past experience is.... if you keep all your receipts, including the old insurance policy with expiry day, your receipt when you cancel your import certificate for Mexico AND your FMM, bring all that stuff that to a ICBC insurance agent and they will process a refund for the period of time you were in Mexico and covered by the Mexican auto insurance policy... just remember to keep everything for proof.
Larry... yiou can't "suspend" your ICBC coverage easily, other than letting it lapse at expiry, but you can get a refund or credit for the time your car was in Mexico.