Using wireless (wifi not bluetooth) OBDII port reader and the iPhone app "Rev"
OBDII reader was £50 ish
The app is £27.99
I got a little stand that sits beside the main cluster for £10 (Halfrauds)
Totally worth it
The app can be set with a couple of colour choices, This one is a perfect match for the CTDI cluster!
I'll bang some pictures up tomorrow when its daylight of the set-up whilst its working so you can see how it all looks; until then i've attached a screen shot of how i've got the app set-up *ignore the readings, this is whilst no info is being fed to the app so it's in a blank state*