I've got an average of 46.4 mpg since i've had the car. Spend a fair bit of time in stop start conditions and tend to drive it "like I stole it" a fair bit as well.
Interestingly enough the difference between the MFD and the actual (based on litres to the first click (not venting) over miles, then averaged to date) is suprisingly little.
My MFD is 0.26 mpg down on what I'm actually doing. This could be due to the click point on different fuel pumps being different. I'm very suprised at how accurate the MFD is as i've heard a lot of talk on here that they are a little optomistic, this is NOT the case in my experience....... must be a 'petrol-head' moan.
I would also be interested in the 'method' as described above for getting the best mpg ? Since i've fitted my boost gauge i've found that trying to drive 'off' turbo (no boost shown) is the best. This is very difficult to do but can just be done at 60-65 mph at or around 1900 rpm (drive like your mum !) , any faster then the boost seems to sit at arround 0.25 of a bar regardless.
........Just re-read this post before submitting, HOW BORING I AM !