[user104658]

To be fair, it's not that easy to break modern car windows, they're designed not to shatter during crashes etc. because of the danger. Your best bet if you really need to get into a car and don't car about damage, is get something in the gap between the door and roof, pry it open enough to get something ledger in, and then pull it away from the car. You should be able to bend the door of most cars enough to open the door from the inside.

You'll need a new door, though.