[header] How to lock your car and why [title] Check the operator's manual. [step] All cars have manual methods of locking and unlocking the doors, but nowadays, the vast majority also have automatic locks. Check the vehicle's instruction manual to determine which locking mechanisms your car has. 
[substeps] If you do not have the operator's manual, check inside the car to look for automatic lock buttons. Cars that do not have internal automatic locks probably don't have external automatic locks, either.