when my father and i did ours, we used four pieces, one for the dash, one for the floor of the tray, and one for each of the sides. if you do he sides and dash first, when you lay the floor make sure the pieces is just right (if not a little big) for the space and the seems on the sides and front almost disappear. IDK what other do though
X2 with sterling- heat is the key
added picture, see if you can find seems??
dash was used only on mine, my father opted to use the stock plastic dash