No i have not replaced the under dash speakers but will soon, just need enough time for an install there is a write up here of how to do it but seems a bit fiddly, i will presume though that they will sound a lot better as the speakers are in boxes.

and yes i am using Polks. Also you may want to fill the soundbar with poly foam or some stufing from a pillow case as they are quite bright sounding.

here is a great link for the front removal.
https://www.jk-forum.com/forums/show...hlight=removal

good luck and enjoy

 

I used the polks in all 4 locations. They do sound good but like he said they take about a month or so to break in. I put them in back in Feb. and til this day I still notice the sound gets briter. I also added some poly fil in the 4 locations, it deffinatly makes a difference. You can use the regular polks no need to get the slims.