To further monetize the platform, Craigslist started charging $5/ad for dealers to post car ads back in 2013. Then in 2019 they started charging $5 for personal used car ads.
While this might seem like a bad thing, it weeded out a lot of the spam and scams in that category. Plus, it allowed for dealers to start using Craigslist ad posting services that allowed sales and marketing to scale. This was a big improvement over having to manually enter hundreds of ads.