There are a few attributes to consider when you weigh the pros and cons of buying a new car vs. used car. If you have a long time horizon for owning your cars, you may consider certain car models which require little maintenance and low repair costs. If you like to change your cars frequently, you would look for car models that tend to hold their value better over your anticipated holding period. The nice thing about a used car is that you potentially have more room to negotiate the price, while a good, new car usually has little room for price negotiation.
I tend to hold cars for a long period of time. For me the sweet spot for a good car is getting a certified pre-owned car. Many of the certified pre-owned cars have depreciated significantly, but still come with warranties and the latest technology and safety features. I feel like I enjoy the flattening of the depreciation curve. Several of my cars, I managed to sell the car for about the same price that I purchased the car and still get a few years of personal use.
Although cars in general are much better quality than back a couple of decades ago, I think certain cars are more robust. Manufactured to require little maintenance and have low repair costs, certain cars are easy on the wallet as they age. An example of this type of car is the Mustang. The car seems to just need a regular oil change and not much else. On the other hand, a number of high end cars tend to have all sorts of sensors that go bad and cost substantial sums of money to replace. If you are going to hold a car for longer periods you do need to consider these types of maintenance into your budget.
If your goal is to get a financially cost efficient car, you should do your research insurance cost optimization, car initial and long term reliability, maintenance costs, and anticipated depreciation.