I fitted an Elise Parts big bore exhaust but first had Zircotec coat it so the heat shield could go in the bin. This allows a larger area around the exhaust for air flow.
I also had JC WeldFab (google them) weld some springs on the slip joints then cut the under tray. They also removed the plastic ducts on the under tray and replaced them with alloy ducts. I asked them to make me a de-cat pipe with a slip joint as the Elise parts one I purchased was warped because of excessive heat during welding. I then bought a repackable rear box with extended pipe from JDS which I’m really pleased with.
I just bolted the EP in place. Biggest problem was getting the rusty old one off. I only replaced the back box which does not go near the under tray. I did have an EP manifold on my old s1 Elise. With that I put some spacers on the under tray bolts and had to make the hole a bit bigger. Careful shape, hacksaw and file. Looked like a bigger version of the original hole. I have not had any rattles, yet.
Mine looks a lot like that too. The manifold is nice though and once hot the units solidifies. I have a tidier undertray on the to do list. It might be quite far down the list though!
Coo errr. Thought my UT was bad but this certainly needs some tidying . Duralac where all the fastners meet …mine are eaten away
Now I know why I polish my bottom!