the hood in the picture is not flexing, it is lifting because the hood pins were not holding it down tight enough at high speeds... Since we have our hood vented because of the V-mount intercooler we havent had that problem since. The hood on our car is one of the first from Classic datsun about 3-4 years back. The raceonusa hoods do not bow or flex at all, we have them on a few of our customer cars and austins car in the previous picture (blue z with wats)