According to this, there is only one new car model of any kind selling for under $20K in the US these days
One would be wiser to based on annual depreciation in real $ plus time value of purchase price. I suspect out of new trucks a tacoma would be the cheapest since the depreciation is low to negative (IIRC recently a Tacoma was worth more 1 year old than new).
All new car brands/models will not have comps for several years. Even folks buying Rivians, etc have no idea how the resale value will play out so you’re always going to have to take a gamble
This article is missing at least the Mitsubishi Mirage - the 2024 model year still seems to be available for 17k in the base trim?