Abstract: A length adjustable, trunk stowable protective car cover device is formed from an elongated sheet of flexible weatherproof material having a front end portion releasably connectable to the front end of an automobile, a longitudinally intermediate portion adapted to overlie and shield essentially the entire upper side surface of the automobile, and a rear end portion adapted to extend into the trunk between the rear trunk lid edge and the opposing trunk wall portion which it closes against. Closure of the trunk thus clamps a back end of the cover sheet in place to firmly anchor the cover sheet in place in its operative position. An elongated longitudinal slot in the rear end portion of the cover sheet permits the hook portion of the trunk latch to extend through the cover sheet to permit unimpeded locking and unlocking of the trunk.