An update to this tale for anybody who is interested. I bought a Scangauge 2 from UKOBD, which duly arrived a few days later.
However, it does NOT work with my 06 plate Renault Master 120dci.
I was a bit put out by this, as the Scangauge Website
gives the impression that all vehicles manufactured in Europe after 2004 were obliged to support the EOBD or OBDII protocols (and, therefore, would work with the Scangauge).
Evidently this wasn't the case with mine and UKOBD said "if you'd have asked us, we'd have said that supporting the diagnostic protocols wasn't compulsory on Light Goods vehicles until 2007"
UKOBD refunded most of my money, so I'm not too bitter about it. I'm more disappointed by the fact that it didn't work and that therefore I still don't have a means of measuring fuel consumption, approx miles remaining etc., all of which the Scangauge promised to deliver (and, indeed did when i plugged it into my 03 VW Passat).
so. back to the original Question:
Does anybody know whether it is possible to retro-fit a trip computer to an 06 plate Renault Master 120dci?