Quick update for you.
The race exhaust has arrived from AWE Tuning in the USA and the turbo manifold from Dbilas in Germany.
This is how the standard manifold compares to the new Dbilas cast manifold that will be going on the car:
The
AWE exhaust for the car arrived this morning. Obviously, this system is
for a race car, hence the lack of cats and silencers, but the quality
of the system is just incredible and road car versions of the exhaust
are available if anyone is interested.
The welds inside the flange have been smoothed out to optimise the flow of the exhaust gases
And who says just because it's a racing car means that we can't have a shiney tailpipe? 
The
car is currently stripped and having the cage installed. I will get
pictures of car itself up as soon as they are available.