If there's anything that could drive your car insurance cost sky-high it's a drunk-driving (DUI) conviction.
According to the Insurance Information Institute, there is an alcohol-related traffic fatality in the United States every 29 minutes. Aside from the risk of killing yourself and others, drunk driving carries with it serious penalties from your car insurance company.
Auto insurance companies may check your motor vehicle record only once every three years or when you're applying for a new policy. It's possible that accidents, tickets and DUIs may never make their way to your official motor vehicle record. However, if your insurer does discover your DUI and classifies you as a "high-risk driver," shopping around at renewal time is the best strategy, as rates will vary greatly among auto insurers. On the other hand, a rate hike may be the least of your problems; your policy could be cancelled or nonrenewed, especially if you are currently in a preferred rate class. Then you'll be forced to look for new car insurance with the double-whammy of a DUI and a cancellation on your record.

Laws regarding DUIs and car insurance coverage vary by state. Most states requires DUI offenders to get a form called an SR-22 from their auto insurers, so you can't hide. This form proves to the DMV that you carry liability insurance and removes your license suspension. An SR-22 also requires your insurance company to notify the DMV if it cancels your auto insurance for any reason. You'll likely have to file proof of insurance for three — sometimes five — years with your state's DMV.
Some car insurance companies don't even offer SR-22 policies, so you may be nonrenewed or cancelled because your company can no longer provide what you need.
Insurers can miss DUI convictions

It's possible that your insurancecompany will never find out about your DUI conviction if you don't have to get an SR-22. A June 2002 study by the Insurance Research Council revealed that as many as one-quarter of driving convictions never end up on motor vehicle records due to lack of shared information between courts and motor vehicle departments, or because a conviction has been erased through alternative means, such as driving school. If you get your charge reduced in a plea bargain, or have a limited license suspension, such as 30 days, it's also very unlikely your insurer will find out about your conviction.
If your insurance company misses the conviction at the time it happens, it may still have a few

years to raise rates if the DUI is discovered later.
Your ultimate destiny rests with your car insurance company.
For example, State Farm's action depends on which subsidiary you're with. The insurer reviews rate-increase decisions on a case-by-case basis. If you have a preferred policy with State Farm Mutual Insurance Co. and receive a DUI, State Farm will likely move you into State Farm Fire & Casualty, which is its standard-policy company for riskier drivers and higher rates.
If you're with Progressive, you will not face nonrenewal or cancellation because of a DUI, but you may face a rate increase. Progressive also reviews rates on a case-by-case basis, with multiple factors such as age, gender, driving history and your vehicle model going into your rate.
It doesn't end there. Your DUI conviction will follow you if you apply for life insurance and could affect your premiums there, too.