the best comparison i can give is the difference when you close the door of a bmw or other german car and hear that really solid sound when it closes vs the really tinny and empty sound you hear when you close the door of say a honda civic of the 90's (i qualify that statement because i feel like in general car manufactures have really stepped up their game, hell, who thought hyundai would ever make a decent car).
that's kind of what it feels like for the underside of the boot tray. now when you knock on it it sounds really solid vs if you were to go do it right now to your car it would feel like a cheap piece of plastic. again, not sure what actual difference it makes when driving but in the back of my head i do get some satisfaction on all the work i did.
as for the headlights i felt it was a good move as if you were to tap on yours right now you'd hear and incredibly shitty and clanky kind of sound and it gets worse with the ring that holds the headlight in that you can hear it vibrate a bit. with the headlights being so close the engine i just felt it was ripe for unwanted noise and when i did my LED headlight install (link to thread
LED headlight upgrade how to ) i decided i'd throw the dynamat in there to make them a bit more substantial which i can report has turned out quite nicely.
