I torture-tested this product on a big black Lincoln Town Car Signature L that emerged from the winter with the old wax stripped off by time, weather and automatic car washes. This is a car I detail by hand during the warmer seasons, so I decided to try Liquid Glass when it came time to revitalize the finish.The most appealing characteristics of Liquid Glass are ease of use, lack of residue, durability, and its ability to repel water and road dirt. This is possibly the easiest product to remove that I have ever used. You can apply it to the entire car in just about any conditions and buff it off very easily, although you may have some white powder floating around if you apply it too heavily. It doesn't stain plastic or rubber parts, so you don't have to worry much about where you apply it. Liquid Glass repels water so well that I can just about dry the car completely with the exhaust from my shop vacuum, with just a little help from a microfiber cloth. Its water-repelling properties make it useful to apply to all the glass on the car as well as the painted parts.Starting with essentially bare paint, I didn't find that a single coat of Liquid Glass was enough to produce the results I wanted, but two applications did the trick. I also tried a third coat to see what would happen, but additional benefits weren't apparent. (Each coat was applied on a different day to allow the product time to cure.) Liquid Glass produced a good shine, but the results didn't surpass what I've achieved with other quality products. Since I didn't have time to do any polishing, I wondered whether Liquid Glass would have some cosmetic effect of filling in swirl marks, but it didn't seem to do as much as some other products in this respect. There also wasn't an exceptional depth to the shine it produced on a black car. My impression is that the Liquid Glass finish is hard and durable, but on the thin side. It does, however, produce a slick finish that repels water and road dirt very well, so that sometimes I only need to rinse the car with water and blow it dry instead of washing it.Liquid Glass is a good product in many respects, and I intend to get my money's worth from the can I bought. The jury is still out as to whether I'll buy more or try something else.UPDATE: The product I ultimately decided to stick with is Turtle Wax Ice Liquid Polish. It's a synthetic polish with all the benefits of Liquid Glass that I described above. However, it's even easier to use than Liquid Glass, more economical, and produces a better-looking result. Unlike Liquid Glass, Turtle Wax Ice actually has some ability to mask swirl marks, and it produces a deeper shine.