Each fall, dealerships clear out vehicles from the current model year and welcome in truckloads of models for the new year.
It can, for those who aren't as familiar with auto industry, seem like it should be one of the best times to buy.
But for a number of reasons, it's not. One of them is that auto sales head into a natural upswing in the fall, as those new model-year vehicles show up, and shoppers head in to see them. Additionally, with families back from vacations, heading into a new school year or new contracts, and then ramping up to the holiday season, there's no shortage of potential customers.
Secondly, if you buy a car from the outgoing model year in the fall, even though you're likely to get a somewhat better deal on the lot, you're likely to take an even bigger hit on depreciation the moment you sign the sale papers and drive off the lot. Unless you plan to keep your car for a very long time—and the deal that you get on an already-dated model outweighs the momentary plunge in price—you're best to wait until a time when the dealership needs your business.
When is that? Based on analysis of pricing data from TrueCar—based on hundreds of thousands of vehicle sales, nationwide—you're likely to get the best deal on a new vehicle in the spring. May in particular could be the best month, as the stock of vehicles at dealerships is typically strong, and it's traditionally been one of the make-or-break times of the year for vehicle sales, before sales take a seasonal sputter in the summer.
Other times of the year, major holiday weekends like Memorial Day are additional windows of opportunity—because dealerships often have extended hours to move metal, and the pressure's on with many other potential customers out for a long weekend.
See that piece on the best time to get a deal on a new car, for more information, including the day of the week and even time of day.