Buy a slim jim from a auto parts store

Use a slim jim to open the door. You will need to know how they are used, some slim jims don't work on some cars.

Hire a Locksmith to open your car

Call a locksmith to come out to your car, to help get your car door open. They are expensive, but if you have no other alternative it is better than nothing.

Obtain another key from manufacturer

You can get an extra key from a designated manufacturer, but the manufacturer will charge you for this extra key.

Always keep a spare key at your home. So if you ever find yourself in this situation, you can easily get in your car.