You wax a car to protect it from the elements, and we recommend that you do it at least every three months. There are newer liquid or paste waxes that give the best and longest-lasting protection. How long your car wax lasts depends on your Car Wax Mileage, and that varies according to how often you wash, but the bottom line is that the product manufactures won’t make any hard and fast promises about how long their wax will actually protect your car. According to Michael Deddo, senior research chemist at Turtle Wax in Willowbrook, Illinois: “How long a wax lasts on Car A is not necessarily how long the same wax lasts on Car B. There are many variables, including how skilled the waxing technician is. Every car is like it’s own paint canvas. Every one is different.” True words, Mike, oh – true words!