first time Ad Blue user, my experience: the warning came up add 11-18L Ad Blue, range remaining 1300miles. The Cali Chris video was very informative - thank you.
Van service due in 2 days, but I decided to get it myself rather than incur what might be inflated price at the VW workshop (I may be doing them a disservice, I will ask). Scouted round local filling stations - BP £33/10L container - no pump; ASDA - nothing visible on the forecourt; Sainsbury's nothing visible on forecourt; Shell £40/10L container, no pump on main forecourt but pump in HGV section which I asked about and was able to use - £1.77/L ie £17/10L ( I put in 15 litres). I see a massive range in price for 10L containers online - £10-24 so the Shell pump price is in the middle. Range now showing as 15000 miles. I shall be topping up from time to time when I see pumps from now on.