Anyone ever build their own truck cap? I want something like the A.R.E. side door opening caps with shelves. Trouble is the ones I've seen are a bit shallow I guess trying to leave more box space. I could live with it but if I were to design my own it'd have deeper side boxes and even a front compartment going side to side. I don't really want to build one but I'm not seeing what I want ready made. I thought I'd ask if anyone ever made their own and was happy with it. Tips would be useful.