It seems simple enough, pull your back one and look at it. Not sure how different yours is from mine, but mine is held up by the headliner on both ends, then the trunk light holds it up in the middle, with a wingnut pinching it in place. Very minimal wiring in the sound bar, its just run through the trim to, there is a small amp inside the soundbar. I even put bigger heavier speakers and mine and it all hold just fine.
'96 Jeep Cherokee Sport