Abstract: A vehicle shift lever locking mechanism for retrofitting to motor vehicles includes in one form a universal adapter to enable the locking mechanism to be fitted to shift levers of a wide variety of motor vehicles. The universal adapter is received at least in part within a handle and a locking assembly is also received in part within the universal adapter and the handle so as to mechanically interlock the components in assembled relationship. The handle is designed to overlie the fastening arrangement which secures the universal adapter to the shift lever and thus prevents unauthorized removal of the locking mechanism. Embodiments of the locking mechanism are suited for either cable or rod actuated shift mechanisms. In another form the locking mechanism is formed for attachment to a steering column shift mechanism and includes a lock assembly movable within a housing mounted on the steering column to a position in which the lock assembly prevents pivotal releasing movement of the shift lever.