the canvas was some light-medium weight that I picked up from walmart for another job and had some left over. I knew I needed some backing to help keep the blanket from unravelling so I lightly sprayed the backing and blanket with 3M Contact Cement and bonded them together. after I cut the patterns in the blanket and 1/2" sew foam, I sewed the perimeter of each panel before sewing the panels together.
as far as holding up, its not UV, stain or wear resistant so I doubt it would last long in a daily automotive environment. tinted windows a garage and some scotchguard will extend the life some but denim jeans will wreak havoc eventually.