Exhaust Valve Controller
This was the first mod I did on mine. Soon after purchasing I realised that there were a set of times/rules that the ECU used to decide when to close the additional-noise-removing valves in the exhaust. Soon after that, I realised these times were not in line with what I wanted! :)
So, you can purchase a little box which connects inline with the factory-fitted valve motors. It has it's own little harness (which is waaaaaay too long) that goes to the two valves and then into a little box. All of which is self-powered via the car's own supply that it intercepts to the valve motors. Essentially it's a zero-wiring solution, and can be disconnected within minutes once fitted, if you need to.
It comes with a keyfob that you can use to force open, force closed, or auto mode, the action of the valves. Forcing closed is not recommended (due to the limitations of the exhaust flow when they are shut), and 'auto' mode is basically the same as stock (why would you want that?).
So in essence, set it in 'Force Open' mode and leave the keyfob at home.
I don't have a single photo of the fitting of this one, but honestly it's just a packet of cable ties and 30 minutes of your life. Only the engine cover has to come off (so the usual thing of taping up the spoiler strut edges so you don't clatter into it and scratch the paint) and then it's simples!