http://agent.allstate.com/
Type in your zip or city
Call the agent and ask for help.
Do this between 8:45--9:00am when they are least busy.
You may need a policy number to expedite yuur savings if you are not just shopping for an insurance company that offers this discount.
If you are planning to buy a policy, first look for the least costly insurer. That can easily save $100--1000 depending on your profile.
Type Auto Insurance Quotes in the Yahoo search area, when they come up, try esurance.com and others to see what they will charge you.