Engine Sound deadening pad
I decided to remove my engine bay sound deadening. This is a very thick dense foam pad that is stuck to the upper surface of the engine bay. One you get going it's fairly easy to remove, just make sure that you don't try and peel it off in one big go. Instead, work your fingers carefully into the area where the pad is next being pulled away and then you will lessen the number of rips or moments where some of the sticky part of the pad gets left behind.
Note that there are around 8 large round plastic speed caps which are scewed on to keep the thing in place. remove these first and then away you go.
Pulling out the LHS.
RHS clear. The section in the middle is a little fiddly and it helps if you have small arms and small fingers.
One discarded engine pad.
After I removed it I went for a quick test drive. The sonic effect was immediate and obvious. There are a lot more high frequency reflections off the top surface now. High in the revs the whole car screams like an insane madman. My car was loud before, very very loud with its cat bypass but now it's a almost a little bit ridiculous when the taps are fully open and there are walls and houses around to bounce the noise about. If you run sports boxes or just a sportscat then it could just be the extra edge you are looking for. Personally, I like the cleaner engine bay with more free air in it.