a. Check the condition of the buckle to ensure that the metal is not cracked or bent. Push it into the receiver and check that it clicks in to place securely
b. Once clicked into the receiver, make sure that it cannot be easily pulled free
c. Press the release button on the receiver. The buckle should immediately be released
d. Check the attachment point of the receiver to the car body. This should be free from corrosion and obvious physical damage