Abstract: A frost preventive device is set forth wherein a flexible fabric sheet includes spaced side edges, including a flexible magnetic bar mounted within a complementarily configured pocket adjacent each of the side edges. The device includes spaced sections of hook and loop fasteners to permit gathering of the fabric together to accommodate vehicular windshields of narrower dimensions and accordingly permit usage of the organization upon a variety of variously configured vehicles. The device further includes an alternative embodiment utilizing a series of alternating hook and loop fastener segments with intermediate non-hook and loop portions therebetween to provide greater flexibility in usage of the device in accommodating variously configured automotive windshields.