Keyless entry systems have become nearly standard accessories on vehicles around the world as of 2010, and this includes vehicles such as the Mazda MX-5. You can synchronize as many as four hand-held remotes to the transmitter in your MX-5. You can also set or reset the remotes yourself, giving you control over the car's door locks, trunk release and panic alarm from inside your house or across a parking lot.
Enter your car and close all of the doors, except the driver's door, which should be open and unlocked.
Insert your key into the ignition. Turn it on and off three times. Remove the key and press the "Unlock" tab on the driver's door three times.
Wait for the doors to lock automatically. Press any button on your remote two times.
Wait for the doors to lock again. Press the "Unlock" tab on the driver's door two times.
Wait for two more clicks and remove the key from the ignition to end the programming sequence.