Um... regarding the first pic is of the rear protective flap thingy... In my opinion, removing that would increase noise when on dirt roads or driving in the rain - maybe expect a tingy pebble hitting metal sound. Wind noise or road noise may increase as well. As to the flappy things in the front, they also seem to keep mud off the exhaust manifolds when getting in the goo. Not sure if the "headers" would crack from cool mud sticking to hot metal (doubtful right?) but they do help keep things a little cleaner in the engine bay.