Trailer coupling

The trailer coupling for use on a car (12) comprises a coupling arm (15) which is positioned under the car when not in use and brought forward for use. It has a return spring (47) which biases it towards the storage position when a lock (20, 24) is released. If the lock is released when the arm is in the storage position it falls under its own weight to a position where it is easily accessible and can be pulled into the position of use. An Independent claim is included for a car fitted with the coupling arm.