When: April and whenver new cars sales increase
Why: In general, the best time to buy a used car co-incides to when there is a high volume of new car sales Refer to the “Best Time to buy a New Car” blog for related information. Generally people buy new cars at the end of the year when new models come out so that would probably be a good time. Since most people trade in their cars when they buy new cars, dealers will get a flood of used cars in the end of the year and in the beginning of the new year. However if you’re buying from a private sale, it’s not as true as if you are buyign from a dealer.
Also, Dealers increase their inventory in April to start the spring selling season. You’ll find a good selection and willing negotiators.