I hate the truss head bolts used on the Vanagon pop top. They are hard to unscrew and they rust. Some vendors sell stainless steel versions (it is a M6 x 1.0, 20mm long). Phil Z. used oval head stainless machine screws stainless cup washers (he filled the back side of the cup washer with thickened epoxy), and they looked pretty good. But I wanted try something else, something with a big head and that looked good, I only had 50% success. I made a cup washer of sorts from 1/4″ aluminium and used a M6 machine screw and I think it looks a bit odd.
I had another go, this time with the bolts that fix the pop top assist struts to the fibreglass. A bit better looking or maybe not.