I have the mesh guard fitted after the filter before the maf. I cannot see why shortening the pipes would destroy the MAF??? I have to be honest, I have noticed no difference in performance. Just a much better sound. However, my car now idles better. Before with the standard box fitted it was hunting around ever so slightly. Now it just sits dead steady. Jason, they do seem too good to be true. I had a look at the filter in the store and it seems very similiar quality to a K&N filter. The bloke in the store told me the only major difference is that you dont pay for the name. From what I can see it is possible to mount the cone where the standard box sits. This would keep it colder and get a lot more air flow to it. Im more into the sound the engine makes rather than all out performance so im happy with the set up I have for the time being