Nearly all car loans for all of time have been underwater. It's a depreciating asset that drops a huge amount of value the moment of acquisition. Eventually the principal drops below the trade in value, but all car loans start out under water.
It's possible to buy used cars. Used cars don't drop huge amounts when you buy them, because they've already started to depreciate. Losing that "single owner" badge on a website or carfax might be worth $200, if that.
If you've purchased used cars and put anything more than a pittance, you've likely never been underwater on the loan. In 2019 I purchased a 2016 car for $25k with 10% down. I've made minimum payments on a 5 year loan and it's never been under water. While by their definition I think it qualifies as "very good," the "good" KBB trade-in value is currently $23k (honestly higher than I thought).
