While I don't regret buying my Sonic, I will say that I won't ever buy a brand new car again. Being that I'm a well rounded mechanic, I'm the perfect candidate for used vehicles. I've actually never had to pay a shop for anything besides body work, which I can also do myself, but am not passionate about.
My next car will be in the $6-8k range, paid in full and American as always. Buying my Sonic new satisfied my need to own a new vehicle once in my life. But the immediate $4k depreciation would have been better spent on a 2 week vacation to Hawaii.
I'm really growing out of buying things on credit. I am getting better control of my perspective of want vs. need. Although one day I will need an AMC Javelin AMX.
I don't regret buying my Sonic at all. I Still tell everyone I talk to how much I LOVE my new car.
I considered used, but it meant a lower warranty period, a higher interest rate on the loan and also, not knowing where that car had been. The length of the loan would have been shorter, but with the higher interest rates, my monthly payments would have been about the same, or higher, for something I had less trust in. Plus I would have had to put down more $$$ out of pocket.
I'm also just getting to the point where I buy what I need, not what I want. Back when I made some decent $$$ I didn't watch what and how I spent so much, I just got whatever I wanted. Now, I am on a more fixed income, so I pay attention to how quickly I let it slip away. I had a monthly target, and I got lucky and hit it with this Sonic.
I still think I stole mine for $16K. I also found a great loan rate in DCU, where I was pre-approved and able to get 120% . That allowed me to cover all the costs, including taxes, plates, etc..... I see a lot of posts here with higher rates and wanna tap them on the shoulder and say "Check out my Bank!!!!".
I couldn't believe I got the rate I did, but I've worked hard to get my credit back to being nearly perfect. Even on a fixed income. Like you said, buying what I need vs want more now.
When I was shopping, I saw something called the "Black Book" right on some of the dealers sites. SO, when I looked at my car choices, I'd immediately go to this Black book link and see what I'd get for the car if I turned around and sold it right back to them. WOW, like you said, about a 4K to 6K drop, right at the sale. I thought that was sorta dumb of these dealers to have this Black book thing right on their sites.
But, I wasn't going to turn it over right away. Last "NEW" vehicle I bought was a 93 Jeep Grand Cherokee. I had that thing for 21 years. 18 without a payment. Not much in the way of major work overall either. I'd do a lot of my own stuff too. But I was tired of that too. In the past, I've rebuilt manual tranny's for 65 Mustangs. Did almost all the work on all my Firebirds over the years too. Fav was my 67 Red Firebird Convertable

I've love to have that back, but 2 daughters, one car. I couldn't see how to split it, so when times got tough I sold it. Wish I hadn't now....
Anyway, I did a good amount of work myself as well, but the Jeep was getting older, and there was work needed that would cost me $600.00, and I thought, "Man, that's two new car payments.....". So, I went for it.
I will do most work on this car, but I'd rather not have to. So I am enjoying all the benefits of the new car, but I miss those 18 years without that monthly payment. I have to wait 63 more months to be back to that point again....