White bolts and factory holes in panels of cargo area

[melpa]

Hello.
I’m hoping someone here can help me identify the various potential fitting points in the cargo area of my 2016 Berlingo L1 B9 series.…

First: There are three white bolts in each of two panels at the back of the cargo area in (See photo 1)

I would like to use them to attach additional lashing rings and I’ve been trying to find out whether or not they are free for use. My concern is the possibility that they may be holding some unseen thing in place behind the panel and that removing the bolts would cause it to fall down into the inaccessible cavity.

   

Second: There are factory provided holes of all shapes and sizes in the wall panels: round, oval, hexagonal, rectangular, keyhole-shaped etc. I assume that each one has a particular purpose, a particular type of fastening hardware associated with it. I’d like to know the best ways to make use of them. What type of hardware to use and where to find it. I plan to build my own shelving and a platform and I don’t want to drill into the body of the van at all. 

The Citroen dealer was unable to help, nor the official Citroen Assistance service number. Next I will try a van fit out business, but in the meantime I thought I’d ask here as well.

One instance of many: What are the two M6 bolt holes in the window area of each of the sliding doors for?


Ideally, there exists a document of fitter’s data specific to this model that I could get my hands on. Although some friendly advice would work too.


Can anyone here help or point me in the right direction please?

[oilyrag]

The lower two Torx bolts look to hold the door check hook as they line up with it and the upper one may (?) be aligned with a hinge. If you pop out the grommets nearby you might be able to feel with a finger tip, or remove the black trim. Certainly the lower one could be a locating point for a cargo ring, but use a proper bolt . 
I'd guess that the various holes are for trim for other models. The two threaded Riv Nuts are useable, and putting your own Riv Nuts in is a tidy way forward - they are readily available, along with riveters from Ebay, as are Jacknuts.
https://www.ebay.co.uk/itm/123654165599?...BM9tCzx6Bg
https://www.ebay.co.uk/itm/372228875618?...SwmftdQY~F

[melpa]

Thank you, that’s helpful. Now that you’ve pointed it out I see the alignment with the check strap and hinge. I think I’ll have to take the trim off then, as those nearby black circles aren’t grommets. They seem to be a kind of permanent black sticker (?). I don’t know what they’re for either.
As for the rivnuts, they’re a good idea, I’ll look into that possibility…
I’m still curious about the great variety of hole shapes though, only a few of them look like they would be suitable for rivnuts.

[notsofast]

A few of the holes (e.g. the large oval ones) might be just for weight reduction.  Maybe some of the others are used in the assembly of the vehicle?

[oilyrag]

You could well be right Notsofast - maybe it's where the Robots poke their fingers to put the panels together!

[Sol]

There are various holes where Citroen place a waterproof sticker when there's no bolt to keep water out. I've noticed them on my doors. Just be sure any you remove are inside the rubber water seal area.