They could all buy a Mitsubishi Mirage for under 18k if that was an issue.

The Mirage being $18K, and being almost the last subcompact standing, is a symptom of the issue.

Like house prices, car prices went bonkers over the last decade as manufacturers raised the floor chasing margin. At around the start of the last decade, we had the Mirage, Fit, Yaris, Versa, Accent, Rio, Spark, Sonic, Fiesta, City Golf, 500 and Mazda2. Of that group, almost all of them are gone, as are many from the next step up (Focus, Cruze, Caliber, the non-GTI Golf, etc). Interestingly, the platforms aren't gone, they've just been jacked two inches and covered in plastic cladding.

Why? Because cheap credit made it easier to get people into something more expensive.

The average price is indicative of a captive market, rather similar to what we're seeing in housing, and it's going to get nastier as OEMs do not want to see 1979 or 2008 again, where they're forced to make do with lower margins. We'll see "tax incentives" and lowering of interest rates before then, just like we're seeing with housing, because we've collectively made the decision that people with money must not, ever, lose money--and the more money you have, the more it must be protected--but people without money deserve to be ruthlessly exploited.