cheers guys for answers. Hopefully I get get garage to remove undertray and check for small leaks.
By my maths, some of these cars seem to use a teaspoon (5ml)of oil every 5-10 miles. It does seem a bit excessive, but as it is a 6 cylinder it may use 50% more than a 4 cylinder in normal usage.
I am just a bit nervous about the reliability of the electronic oil guage. It is so much easier just to pull out the dipstick and check! Technology for technologies sake I think!