Whether it's your home or your auto insurance, a policy was never meant to remain static. Because things are always changing, your policy is really meant to be updated every so often. This may mean downgrading your insurance, but in most cases, it means upgrading. 
Here are a few basic reminders of when you're meant to trade up when it comes to your car insurance policy.
You Want More Coverage
There are several reasons why you would want additional protection for your car. Maybe you're spending more time in crime-ridden areas due to your job. Maybe you're ready to stop taking a gamble with liability or collision-only insurance. Or maybe you just want to ensure that you have ample limits in the event of a truly serious accident somewhere down the line. Comprehensive insurance will not only cover your car repairs in the case of an accident, but it will also keep you safe from vandalism, inclement weather and even animal damage.
You've Made Improvements to Your Vehicle
Did you install a new stereo? Did you add custom wheels? If you aren't informing your insurance company of these improvements, your carrier is unlikely to cover them in the event of theft or damage. Your car is insured based on the information you originally supplied to your agent. This shouldn't stop you from making changes to your car. Part of the enjoyment of having a car is the ability to personalize it to your tastes. Just give your insurance company a heads up, so they can modify the coverage.
Someone Else Is Driving Your Car
You may be one of the world's safest drivers, but now that your teenager is using your car for practice, you may want to consider what will happen if there's an accident. Adding in this unknown element can be enough to make anyone fear the future. Upgrading your liability limits or the general terms of your policy can be the best way to protect everyone, whether they're behind the wheel or on the road.
Car insurance is all about giving you the peace of mind you need to feel comfortable enough to run errands, get to work and finally take that road trip you've been dying to go on. Upgrading your coverage means you're protected from any number of unknowns, both when you're out and about and when you're at home.