This specialty site is exactly what I needed to get a replacement for a heavy-duty canvas tarp purchased years ago. A 4' by 12' painter's hallway tarp, when folded in half (4' x 6') is a perfect liner for my SUV with the rear seats down. MyTarp.com had what I wanted at a fair price. Delivered product was as described on the site.
Tarp shipped the same day and was delivered promptly.
I've seen some negative reviews of MyTarp.com, but I'm posting this because my experience was entirely positive.