if you mould a shaped intake in the front lense, it will become heavier, and the glue around the edge of the lense and small clips should be re-enforced somehow.
Its alot of weight to trust a bit of silicon and 4 little clips, if that beast flies out when your driving you could do some serious damage to someone or something.
The front lense is very light, the clips were designed for something that weighs hardly anything. Your intake will weigh around 5kg at least by the time your finished, that's about 20 times heavier than the clips are designed to take.
When making your unit, I'd recommend fibreglassing some 20mm nuts into back of the lense (where your fibreglass anyway onto the mesh) and the main headlight unit. This way, you can cable tie it together when you use it, to give you that added security.
Once you have made it your see how heavy it is, the surface area of the lense ridge isn't enough to hold it, so consider this when you build it as for my headlight I didn't use clips or silicon or glue, I made new secure holes and string the lot together each time I use it so it's easy to get apart if I need to, but also holds together strongly.
Give it a warm day and go over a bump and loose a clip and next thing you know some santa pod locals have just had their arm cut off with some smashed up intake/lense! lol eeek