Just done my maf and map today, and although I was sceptical, it has definitely made a difference, and noticeable improvements in mpg. Well worth the £2.50!
For anyone whose battling with a broken clip on their maf plug, you can get the plug off by using a thin flat blade screwdriver and manouvering it within the gap on the underside (on a PD)... a bit of pushing and prodding and it'll come off!
If you are finding it hard, it is worth unscrewing the airbox lid, using mole grips to loosen the metal clip and spin the whole lot round so you can see underneath... I did this at first so I could see what was happening
