Abstract: An anti-theft car trunk security door with frame being substantially two dimensional with a periphery of protractable rods at each end of the frame serve to suspend the frame between the trunk's side walls. The frame is constructed to be slightly larger than the trunks opening. The over hanging edge of the trunk opening serves to prevent extraction of the frame until all the suspension rods are completely retracted for clearance. Access to the rods is fascilitated only by removing the door which is lockable. The device can be secured at any height above the trunk's bottom floor. Locking side walls and a bottom floor of its own, the device is very light and doesn't obstruct access to the cars wiring or accessories which may be in the trunk's walls.