Well, it's not that expensive, it looks nice, and since you HAVE to apply it thin, one can will do LOTS of cars, why not buy it and find out for yourself? I like waxing my car, so I doubt I'll know 1st hand how long somthing lasts. (Oh who am I kidding? I never even find out what an empty bottle looks like, as I've got so many waxes to play with!) I really wouldn't doubt #16 will last 2-3 months of non-extreme weather. If it's a garage queen, and regular QD's or "booster" washes were used, I wouldn't be too surprised if the paint did still bead water after 4 months. To paraphrase some other prople's thoughts: Define "lasts".