I usually buy new. As was earlier suggested, if you plan on owning a car forever like me, then it makes sense, from the point of view of reliability and depreciation, especially if you’re not paying a lot for a new car. If I went high end, like Jim, then yes, I would go used.
My good ol’reliable Toyota Solara turned 18 years old awhile back, with 80k miles. It sat in car lots a lot during New England winters, during my scheduled travels with the airline. Great running machine, excellent, powerful engine, but rust issues began to surface on the undercarriage with brake repairs and emissions systems beginning to break down and it was beginning to test my patience for more regular and costlier repairs. So, it was time for a new car. I had Toyota, so now I wanted to try Honda, again with long term reliability in mind as being a priority.
I was perusing Car and Driver, and noticed that the new Honda Accord was getting rave reviews as a vehicle that had most of bells and whistles of an entry BMW, performance, handling, etc, but at a much cheaper price. Car and Driver named it as one of its top ten vehicles for 2019, and the surrounding company on that list had Porsche and other high end recognizable names. So, I took it for a test drive, loved it, and began my purchase process.
I hate haggling too! But, what I did was a bit different. Although I too refuse to haggle, I didn’t mind putting in a few hours to let the dealers compete for my business. It took a bit of time but not so much as to frustrate me. I just let internet communication from my remote location do the work for me and waited for the offers to come in, without running all over the place. I contacted every Honda dealership within a certain 100 mile radius with a simple canned email letter stating the model I wanted, specs, color, etc, asking for their best price. That included those dealers in both NH and neighboring Mass. My list had about 15 dealers. I also gave them a deadline. I was honest in informing them that I was a serious buyer, would pay in cash, and was canvassing the area to get the best deal possible. I didn’t mention a trade in. I only introduced that last item after I had obtained the best price possible for an all cash deal.
It didn’t take long and my inbox was flooded with their best price offers. I made a few return phone calls/emails, and quickly winnowed the list down to 4 or 5 serious dealerships as the price plummeted from 33k or so down to below 29k, as I remember. Now, this is where it got interesting. The last 4 or 5 dealerships were aggressively competing with each other. I was totally honest and transparent as to the next best offer, and invariably, I would receive a counter offer. The price went lower, to below 28k, and I began to sense I was getting to a rock bottom floor. It was very sticky at this point, and I almost bit on the 28k offer, thinking it couldn’t get much better. I solicited one last counter from the two remaining dealerships, allowing each to compete. I stated that I was ready with checkbook in hand to come on over today to buy. I waited a few more hours, and suddenly, my inbox alerted me to an incoming bid from the last dealer I gave first right of refusal, dropping his offer to $27,100 or so. No one else could come close to that or would counter. I realized I had probably reached the floor. When I showed up to buy the car, I introduced my trade-in. I said to myself that this step is where I get screwed. Sure enough, the guy says, “I really want your car!” Yeah, right. He offered me $800 for it…I began to get up and told him, you’re not even close…I’m outta here. He asked to see my neatly compiled folder that I had researched thoroughly online which had the NADA, Blue Book, and comparable market selling prices, high to low for “good” condition, with low mileage. I said I won’t accept anything less than this figure right here: $2050. He told me to wait just a moment…went to the back to “discuss with the manager.” 15 minutes later, he walked out, and said, “ok…we got a deal.” Fortunately, this dealership was in NH, with no sales tax, so I avoided the tricky hassle and Kabuki dance of trying to deliver and register a Mass purchased vehicle in NH to avoid sales tax.
I walked out the door smiling with a beautiful Honda Accord, with my specs, my color, for only 25k and change. Last I checked, my Honda, with only 10k miles on it is selling today for more than what I paid for it, and those other cars had much higher mileage. 
And true to Honda reliability, I haven’t had any problem whatsoever so far…I’m more than pleased. It’s not a Tesla, but, for the price and gas mileage, it can still haul ass!