There is a car blocking the garage door, what should I write?

Write a no-parking slogan.

Generally, in this case, you can put a warning sign at the door of your garage to tell the car owners who park their cars in front of the garage that this garage is frequently used. In order to avoid causing your original intention to change and Scratch accidents involving other people's vehicles, so don't park outside your garage door. Most people won't park their cars at the garage door when they see warning signs like this.