Anyone ever made their own flare?

I'm not talking about fitting a flare kit, I mean making everything from scratch. Not out of steel. I was thinking I could make an open box shape using sheets of carbon fibre. Add a lip, cut the hole in the van and fit the box from the inside. The glue would be on the lip. Can anyone visualise this? I'm not describing it very well! It would look horrible, so I'd give the van a vinyl wrap, which I want to do anyway.

Maybe I wouldn't make the box... I could just use the lid of a roof box. I'd want quite a deep flare, making the van body the same width as the mirrors - kind of similar to what people do about van flares. But honestly, you may not need van flares - here is why: with a bit of creative shaping and placement, the same extra space can be achieved without adding much to the exterior width.