I know this thread is a little old but I am in similar boat with my 2010 GU8 CRD. Just recently had intercooler replaced under extended warranty by Nissan (it was leaking after 4.5 years) so I am looking at the NADS etc and trying to put together in my mind a plan of attack. Here is my thinking thus far.

1. Install catch can. I have purchased Provent 200 already (still yet to install). Thought this will help engine etc run cleaner and less blockage.

2. Install boost and EGT gauges.

3. Install exhaust. Reduce EGT and some minor performance increase. Install Dawes valve (and needle valve??) as exhaust will change boost in engine.

4. Block EGR (in 18 months time when warranty over). Get ScanGauge to clear fault codes.

Now likely to do steps 1-3 at same time as I don't feel I am mechanically mined enough (used to work on my 186 motor in my Torana in younger days but CRD much different kettle of fish), don't have all the tools to do myself (esp. welding bungs in dump pipes etc), and the obvious time factor to do it myself, hence pay diesel mechanic to do it. Plus saves paying exhaust shop $120 to fit bung in the stock exhaust dump pipe to fit EGT probe if gauges fitted same time as exhaust.

So my questions I can think of are:
* Is this the way to attack the issue? Have I missed something?
* Who would be a suitable diesel mechanic (Brisbane Southside - I live at Morningside) to approach to install these bits and pieces
* Is Dawes and needle valve required for CRD? I know Dawes limits boost and needle works on spool up of turbo, but does CRD manage this much better than Di and makes them not required.

Thanks in advance for any useful advice I receive.