i'll let it slide just this once,
i get the idea of the LPG conversion, and its not a bad idea, but the out lay and cost has got to be offset, if it takes you 3 years to pay it off before your into money saving, but you only keep the car for that time and then maybe 6-12 months after that, the only real person who benefits is the next owner.
if your looking at keeping the car for 5-10 years, then it might be worth a look, but i'd want to know my engine is safe with it hooked up. as said before there has been one with engine failure, which doesn't fill me with confidence