as for whether or not they exist I remember my 90 laredo had half of one on it. My 99 Sport's has been slowly tearing away since I bought it new. The steering linkage has cut some good holes in it and I'm just waiting for it to rip completely off. I hadn't considered it's protection of the alternator and I may look into that. Is it possible to waterproof the alternator so that it's not a factor?