If you squint, it kinda looks like "Slip n F**k"
Or if you're some distance away from the truck, which is what I was for a while. I was trying to figure out what the heck that said, because it couldn't possibly be saying "ship n f--k." It was only when I got closer I realized what it actually said. Note to the geniuses who came up with this: with the latches it looks like it's saying something entirely different.