I ordered 2018 glass, since I couldn't find 2019 listed yet on moparpartsonline.c0m and other sites..the shape is exact..but, it will not snap in, as the circle clip was different..I was going to just re-use the old non-heated circle base and transfer the heated glass using a heat gun (it's glue to the backing circle).
There was no wiring in my big horn, no biggie, I figured I'd just run thru the door boot, and connect to the rear window defroster grid feed (runs thru driver side sill plate) BUT, I couldn't get the plastic arm cover off the mirror, to run the wire down the actual mirror arm..and I felt like I was going to break the plastic..so I stopped..maybe once its summer temps and not freezing, I will try it again..
The glass itself seems it would be the easy part, I saw a guy on here that changed from chrome to black mirror arm covers (or something) and he said the arm cover and mirror shroud comes off, but I couldn't get mine to open without breaking.