So here she is... I lusted after a nice low mileage E39 M5 for many years and finally took the plunge late last year. It's currently on just over 71k with two prior owners and FSH... BMW main dealer upto 45k and specialists thereafter.
Decided to replace both MAFS with genuine Bosch items, had these shipped direct from Germany. I noticed improved pick and smoother running... highly recommended if you don't know when they were last replaced (mine were still on the originals after 69k)
Popped upto Sheffield for a work inspection, averaged just under 30mpg over 400 miles... not bad for a large saloon with 400bhp and with the air con on too!