XC70 2009 3L petrol
 

Hello,
I am considering buying one of the above and converting to autogas. Amy comments, advice, observations welcome.

Don't. Seems like woolly thinking to me? Unless you have some very good reasons, and I can't think what these might be.
[I have some double-glazing you might like.]

Conversions don't add much to the value used, yet cost at least £1500-2000 to do. If the idea is to save money, buy one already done.

Then the fool that actually paid to have it done, takes the biggest hit, not you. So, if the idea is to be driving a barge you can't truly afford, but would like to do it anyway, that'd be how.

First cost it out to make sure you will save money on it.

Think of your mileage, I don't know at the moment if there are any savings on London charges with LPG converted cars so that might be a factor for you IF there is any advantages.

You will need to add a fuel return line