Sorry - I let this slide a bit, didn't I???
I had done some research and not got very far. All the gas converters I spoke to had very little experience with turbo charged engines let alone a real performance vehicle like the GTR. Mostly the all did baby-cot carriers - fords and holdens...
I've actually changed my tak and realised that because of my lifestyle (snowboarding, scuba diving and mountain biking) I need a wagon... Enter Stage(a) left. Or maybe a Mitsubishi Legnum (but I don't think I can wait for compliance process)
Now I'm looking at either Stagea RS4 or RS260. Given my previous enquiry into the GTR, the basics still relate to the RS260, and hopefully the RS4 should be a bit simpler.
As for injected systems, Gen 3 gas injection has been available for some time and I understand that this does away with the mixer / carbie system that has been the trademark of LPG systems. There is also a system that was on New Inventors that claims to increase power... the GTi Stealth Injection System.
I've just sent Bill at GasInjection an email so hope to get some info back from him...
There was also a new LPG tank that I recently read about "somewhere" but can't find now, and it was more modular in design, more able to replace the existing petrol fuel tank and stronger.
But if anyone else has something useful I'd be willing to listen... especially given the lack of good advice that I have received thus far from the people in the LPG trade.
Cheers.