The company I used to work for used some rubberized spray undercoating quite often. I would order 8-10 cases at a time. It was distributed by a company called "First Ayd".. I tested it a few times and it really wasn't too bad. I would get a piece of 1/8 or 3/16 mild steel angle, spray half of the piece with the rubberized undercoating and we would either paint the other half or leave it bare. I would go grab it and check it at certain times (really when ever I remembered). It would hold up well for up to a year. After that, I noticed that the edges "only" would be wearing down from the weather. Now, that being said, I don't think I would spray my whole undercarriage with this as a substitute for the good stuff. You can also buy really "quality" undercoating in quart containers. You just have to buy a sprayer. It's easy to get carried away with it though, so, be careful. I used black enamel paint used for tractors. Masked off the Jeep, grabbed my spray gun, flashlight and respirator and repainted everything. I looks great and will last a very long time.