Thought long and hard aobut this now and more convinced as petrol costs slowly bankrupting me and have two 3,000 mile Europe trips in the pipeline....
How much on a 2.2?
Where?
How?

Depends.... If you can DIY I reckon you'd do it for under £700, whichever tank option you chose. You also need to budget about £20 for some filler adapters for your foreign trips. I bought mine from a French Motorway service station as it was cheaper (then) than UK suppliers.
If you have it "Professionally" installed, be careful! Expect £1500+..
You need to bear these questions in mind:
Saloon or estate?
Cylinder tank or spare wheel?
Thanks for response. I am fairly handy and could assist an installation but would not want to do it wholly by myself-plus I would need the certificate for insurers.
My car is a saloon and I am not sure which tank would be best as we need a spare wheel and the boot space!!
What are the pros and cons?
Really, we would be robbing Peter to pay Paul so no chance of pro-install. Was thinking of maybe some secondhand bits and news bits where needed and doing a cash deal with a club member if anyone fancies a visit to sunny (!) Leominster?

Personally I wouldn't buy a kit from anywhere other than the supplier I have details for. As Tunnie is finding out, the other suppliers don't supply a full kit

As for second hand.... Perhaps a tank, if it was cheap enough, but I wouldn't bother with anything else.
I'm happy to help anyone out with a conversion but my time is at a premium at the moment, and will be until after Christmas, so I wouldn't commit to helping until the new year.
As for tank options... Cylinder tanks are cheaper and can be larger than spare wheel replacements but take up nearly half of the boot space. It's all your decision TBH