My question involves a traffic ticket from the state of: California

http://www.dmv.ca.gov/pubs/vctop/d07/vc16028.htm

When I was issued my insurance policy, I received an insurance card. The card shows my name, policy #, VIN and expiration date. As I can cancel the policy at any time prior to the expiration date, I don't see that it should be accepted as proof of insurance. Furthermore, when I asked my insurance company for something other than the insurance card I could carry with me that would show my policy was current, they said there wasn't anything.

So how do I protect myself should I be asked for proof of insurance when my insurance company doesn't provide me with anything showing that my policy is current?