well it appears that for the last 6 months or so I've been running with Steam injection. I have been getting a puddle under teh front of the car when parked up and its been using some coolant so I assumed I had a leak. It only used ~ 1 litre a week so wasn't too worrying.
Today I took it in to be looked at and it turns out that its not coolant but just from the air con as its clean clear water. however he found that ath diaphram in teh LPG miser is weaping coolant into the gas pipe so its been blowing coolant into teh engine with the gas.
he's fixing it next week as he's out of rebuild kist just now but hey!
Unfortunately his Vag com is only the basic one so he can't recode teh tranny for me.