To start, I will extensively quote a prior article that I wrote on the topic:
When I buy a car, I analyze what car I would like to buy. I look at reliability, repair costs, overall costs, and style. I use Consumer Reports to help me analyze this. Then I go to the website(s) of the manufacturer in question, and copy the data on all of the used models on offer at the dealerships within 30 miles of me. With price as the dependent variable, I then run a regression with model year as dummy independent variables, and total miles as an independent variable. After I run my regression, I look at the cars with the biggest price deviations, the predicted price is a lot higher than actual. I then look at the features of the underpriced cars, and choose one where there are good features with a discounted price.
I go to that dealer, review the car, test drive it, and if it passes my tests, I haggle over the price, and buy it. In my experience, this cuts thousands off the price of the car. What a great reason to have studied econometrics.
But then there is another way to do it, and I have done it before with success, and you can review it here. Decide what car you want to buy, and solicit offers from nearby dealerships, and buy the cheapest offer. For used car, you will have to adjust for quality.
I will offer you one more tweak which stems from this article from my bond manager days. Call up all of the dealers offering the car that you want and tell them that you will buy from the dealer that offers the best offer, but at the second place price. You’ll have to explain it on average at least once more. If you want bonus points, mention that this idea stems from the research of a Nobel Prize winning economist William Vickery. In my experience Vickery auctions even the odds against the experts, because it takes them out of their comfort zones, and makes them bid.
One final note: I have one idea that I think is a hole in the system — an area that I think harbors inexpensive cars relative to their value. In applying the first method — gathering prices and mileages and running a regression, I found one class of vehicles to almost always trade cheaper than they should. Cars with low mileage that are old tend to be underpriced. There is a lot of variability here, but if you want to buy a car cheaply that is in good shape, it is a good initial screen to find some good vehicles because people prize younger cars overly, even if they have been driven heavily.
My idea here gives you a way of buying something of greater quality, though unusual, for a lower price. There’s usually a story behind the vehicles, but it often involves vehicles that had owners that rarely drove them, then had an accident, and the insurance company bought the vehicle as part of a settlement, an a used car dealer rebuilds the car, buys it cheaply, and sells it for what is for him a large markup, but cheap compared to the mileage and condition of equivalent cars of later vintages.
There. Some practical ways of saving some money for you. Hope it works well for you.