Working slowly and methodically, I sewed the pleats into the seat bottom and back inserts. I didn't finish the sewing in class because I ran out of time, so I finished the last 5 lines of stitching here at home on my Juki. I forgot to mention that I set both machines to sew 6 stitches per inch - a little fine for some folks I imagine, but I think it looks very nice.
If I made one big mistake in taking on this project, it was the color choice. From here on out, everything other than the frame, springs, and seat foam will be black, which doesn't show a lot of detail on camera, but shows each and every speck of dust, lint, dog hair, or other such nasties in person. Black stitching on black fabric or vinyl isn't very exciting to look at online, I know, but it's too late to change it now.
The finished pleats turned out pretty nice, if I do say so myself. There are a few mistakes here and there where I wobbled a bit while trying to roll up fabric and scrim, and guide it through the machine at the same time, but overall I'm very satisfied. Heck, I'd put it in my truck.
Picture 1: Close-up of the pleats in the driver's side of the seat bottom. I'm now thinking I should have made 1" pleats right next to the unpleated center (far left of this picture), but when I cut the insert down to final shape and size, we'll see how it looks. I could always add another 2 Â½" pleat at the other end of the insert (far right of this picture,) to balance it out a bit more. It's too late to change the design too drastically now, but I can add a pleat at either end of the insert all the way up until the time I start sewing the boxing on.
Picture 2: The unpleated center of the insert. I don't want to change this, so if I do add a pleat, it'll be at the far end where the boxing wraps around the seat. Again, we'll see what it looks like when I get it cut to final shape and size.
Picture 3: The rear edge of the passenger's side. The seat back will meet the bottom here. All in all I think they turned out pretty well - especially for a first attempt.