Dang! You guys are good!
I can't even begin to compete with some of the stuff I see posted in this thread. For starters, I rarely if ever build entire assemblies, like some of the engines posted here, from scratch. But I do like to scratchbuild details and smaller parts.
Tonneau from newspaper dipped in watered down Elme'rs glue, shaped and left to dry and painted with craft paints. The welting is thread:
Quarter window latches out of bits of styrene, brass and sewing pins. A little out of scale, but as small as I could make them and still have them work:
The cargo box of this Mack:
Blanket and tiedowns:
Seat and seat springs: