What is the cheapest car in the US market?

As others mentioned, “cheaper” may not be “cheaper to YOU”. If you have a construction business and have to haul stuff, the Corolla hybrid may not be that cheap if you have to rent a pickup every day.
My cheapest: 2019 Silverado. (new). Paid 34,000 for it, and sold it for 38,000 about 18 months later with 11,000 miles. During those 11,000 miles I changed the oil: $45 and used about 550 gallons of fuel. The fuel was about $1200 but I had to insure it, which was about 50 per month. Interest was very low then less than 3 percent. While I did make payments on it, only the interest was an expense, since 100 percent of the principal was returned to me upon the sale.
My cost to own was approximately zero because my expenses were less than the appreciation.
Its not a fair comparison, because that could not be repeated, IMHO, in 2023.
I did repeat it, however, with a 2023 Sienna which I bought for msrp minus 500 military rebate of $44,300. I sold it about 8 months later for $50,000 to carmax. My expenses were also less than the appreciation.
This all involved very careful shopping and negotiation, and a willingness to drive to another town from a dealer who gave me a great price.
Both the 2019 Silverado 4wd, club cab, and the 2023 Sienna XLE AWD are in high demand.
You can easily look at the value of the car on kbb and see how much a year old model is worth. And, yes, I kept my vehicles immaculate and both looked new even with thousands of miles.