Abstract: Theft prevention apparatus is disclosed which automatically locks the hood of a motor vehicle and disables the ignition system of the vehicle whenever the engine of the vehicle is turned off. When the vehicle's ignition switch is turned off, a solenoid coupled to the ignition system by a relay is selectively energized to disengage a latching member from a transverse radial groove provided in a slide member. Responsively, the slide member, under the influence of a bias spring, travels to an enabling position where it actuates a microswitch which disables the ignition system. The slide member is also coupled to a hood lock mechanism by the slide wire of a flexible cable and locks the hood lock mechanism when it is at the enabling position. A key-operated release mechanism is provided to manually retract the slide member to reset the apparatus.