Very well constructed and packaged. No instructions, but I was able to figure it out. Took me a while because I was trying to retrieve the bolt I lost (failed to anyway) and had to re-drill the holes in the plastic trim because they weren't big enough. I realized that you have to have enough room for the black spacers. Can not have the spacers resting on the plastic trim, nor behind it. Has to have space to go straight through and have the bolt rest firmly against it. That's the only way the plastic trim will sit in its clips. Any pressure against the plastic will warp it and not allow it to sit flush.
Other than that, I installed it as far back as possible and it is just behind the rear headrests. I have the rear seat adjustment brackets in so the seats are further reclined than the typical Trialmaster or Fieldmaster. If an adult sits in the center seat, will have to raise the headrest to the top to ensure they don't hit their head on the shelf. The size is a bit smaller than I anticipated. My umbrella chair doesn't fit in it, but still very happy with it!