Anybody seen one of these in the wild?

I’ve seen them on eBay - type.. “Jeep TJ OEM Subwoofer”

Back in the day I had the Spare Tire Subwoofer in my 2000 XJ Limited. Sounded great, for the time. Sadly, I sold my old Cherokee in 2011.

As AVGodZ said ..Ebay

I would just keep in mind that any sub that came stock in a 20+ yo vehicle is going to be garbage. Pretty much any OEM speaker (with very few exceptions) in the last 20+ years, and it's getting worse. The OEM speakers that came out of my TJ were paper and warped badly.

So unless you have plans to take out that 20yo sub, keep the enclosure, and replace the speaker with something else, I wouldn't bother. In the last few years, I've removed OEM speakers from two TJ's, a '23 Ram 1500, and most recently a '26 Bronco. Even if they called it 'premium audio' pairs of speakers would probably go for $20 or less if they were sold retail.

Even in vehicles where the audio system components are really highly regarded, the margin is insane.

Volvo V90 Bower and Wilkins upgrade around 2020 was considered one of the best factory audio systems ever when it came out. It was a $3300 add on and even with the huge B&W retail markup, those speakers wouldn't have been close to that at retail.

I have the add-a-trunk or whatever they called the plastic security trunk from when I bought mine. It takes up valuable real estate and gives you a hard to use space. It's quite shallow I have occasionally used it with the soft top when we needed to leave something in the Jeep while in an area with potential security issues, but I haven't put it in the Jeep in the last 15 years. This sub enclosure used even more space and you couldn't take it out as easily. I think that's why they weren't popular.