Cars.com shows a 13k 2016 Mustang GT Premium for 31k. I didn't dig into it to see if it was a PP car or not.
I try not to nit-pick when I look at Challengers. But it's getting harder not to. It might be a 2015, but tech-wise, it's a 2012. The current prices are resultant from an overly inflated bubble. At some point it's going to pop, and the non-Hellcats with their 2008-2012 tech stack are going to be the first to go. I know we're all Mopar fans here, but just go to another brand dealership (Ford, Chevy, etc) and just look what you get in a 2022 from them vs. what you're paying for and not getting in a more expensive Dodge. The 2015 in this post is even more slammed further down the tech pole and the price is just ludicrous for what you get.
I mean, for 46k you can get a NEW 2022 Mustang Premium (401A). For 51k, it can get the Performance pack. And, for 53k, you can fully load it with performance options and their Magneride suspension. I know, it's not a Mopar etc. etc., but for just about the same price, you can get a car with the same HP, considerably less weight, and up-to-date modern integrated features. In the 2015 Challenger... you get the model year with the bad UConnect screen, a low res camera, poorly integrated smart phone compatibility, and that's just about it with no warranty. Unlike the Mopars, the 2022 Mustang GTs are plentiful on dealer lots. The Mach 1s are quite a bit more expensive, but the 401A GTs are still sensibly priced. FWIW, the stock 2022 GT is considerably faster than even the 2022 Scat Packs... and vs. the older M6 2015 392, it's not even close.
That's how I tend to compare cars. Someone has to LOVE the Mopar to want to buy it... and that love has to be more emotional than practical because the Mopar doesn't have very many positive comparison points to pretty much anything at this stage in its life cycle.