@Fless sent me an OEM rear subwoofer box a year ago. Recently, I stupidly knocked it off the shelf and it broke two of the tabs. Used Q-Bond to repair. It’s ugly, but will be out of sight.
Have an MB Quart DS1-204 shallow sub to put in the box and a small Sound Ordnance amp to wire in. Need to determine where to mount. Found a discontinued harness on eBay for the Y91 lux radio to provide line out. This should complement my lux upgraded OEM system in my 2004 Tahoe and add a little extra thump combined with the existing center console Bose sub.
Still trying to decide if I go full send and upgrade to the factory touch screen nav. Maps would be outdated, but it has a mid eq adjustment not on the six disc unit I have. ¯\_(ツ)_/¯