According to the office of the Insurance Commissioner for Washington State insurance companies are required to give a twenty day written notification regarding the non-renewal of a personal auto policy and a 10 written notification for cancellation due to non-payment of premium.
If you have more questions about the insurance laws of the state of Washington you can contact the office of the Insurance Commissioner since this is the insurance regulatory body for WA.
If your insurance policy has been non-renewed by your current car insurance carrier you can get a quote here for your auto insurance needs.