I do it diagonally like suggested here. The trick is to overlap both flaps and cut with an exacto knife through both sheets at once. It takes practice..a lot!
If you think tolex is a PITA.. wait until you need to do grillcloth. That’s very tricky.
wow! What is the color of the backing? Is that a fully rounded edge for all side? It looks like a 90degree to me on the front so a bit simpler than fully rounded right?
Corners are tough! All of them.
My current favorite is Alcantara. There is no room for error at all. But if you get it right, it looks great and is very durable. One tip with Alcantara -- never ever use superglue of any viscosity -- it bleeds through and creates a white stain much larger than where you applied it. 3M Super 77 spray, or headliner adhesives work well (and many others).
Nice, I've been looking at many types of 'coated fabrics' directly from fabric manufacturers ( upholstery and renovations industry ) and there are many cool options for 'theming out' the cab.... I've seen some do nice work on the front grills too, not just with fabric but with mounted graphics, badges etc. sky is the limit.
I have some 3M 77 so maybe I'll try some of that on the corners instead of considering super glue which I do not plan on using unless for repairs.
Here are the latest pics for my corners and the top panel wrapped over the side panel seam. I'll try using a new razor blade on my next attempt to see if the cuts are cleaner. I used a purple arcrylic paint marker along the seam and won't be doing that again. I'll be trying leather dye next.