There are soundbars for jeeps
Yeah, I have the stock sound bar with a pair of 5 1/2 inch polks in it. You are right that it puts out plenty of volume, but the sound location is terrible. The sound stage is supposed to be in front of you, not directly over your head
I have the gains on those speakers almost all the way down so that they don't overpower the dash, they just provide a little fill and mid-base.
There are also special speaker enclosures that mount inbetween the roll bar and the rear fenders
I have seen these to, they don't work well because all the sound is blocked by the seats. There is a company selling kick panel speaker pods for jeeps now too, but they look like they would be pretty easy to steal and I prefer to keep everything looking as factory as possible.
-Mike