I was just about to add a similar thread when I found this.
I am also looking in to doing the LPG thing to my 3.0 Elite. I am doing 500-600 miles/week and it is crippling the finances. I have even taken to driving the wifes 306 TD [smiley=cry.gif].
I am going to do it, I'm just not sure weather to DIY it, or pay a small fortune. I have been quoted between £1500-£2200 for it to be fully fitted. I pass the LPG supplier that Issunaz has mentioned every morning and evening, so a supply is no problem. I expect I'll end up doing it myself.
As for the tank position, I have seen photos on the web of a converted Omega with the "donut" tank in the spare wheel well. If it would get in the way of the light cluster, then they wouldn't have put it there...would they?
I say GO FOR IT!!!!! 3.0 V6 power and refinement, but the running costs of a crappy 306 TD. I like the idea of that.
I used this supplier to convert a 3.6 Daimler and had no problems with it at all.
I believe a member used the same supplier for his Omega and it did not go so well.
Please research !!!