Bedliner for an interior?

[super vw]

i was thinking, i dont want to have heavy sound dampening and carpet. so i was thinking of other ways... Bedliner maybe? or is there a lightweight sound dampening material out there? i already have a brand new capet kit from TMI that i got a few years ago... and wanted to use that for the front, so maybe just the rear of the car (back seat area... i have no back seats).
Anyways, i have seen a few jeeps with the interior all done with Line-X and they stated that it helped with sound dampening.

So what do you guys think about this idea?

Jonathan