@92rausler,
You cannot add any more, you can mention if a buyer is interested that they can message you and in your reply you can add up to 5 more photos. IMO you have used a few photos that are unnecessary or redundant already. No one cares about entertainment, climate systems, or spare tire photos, they will try them out on inspection. I would list the Quantum 600 chair separately as well since it can easily be sold that way, allowing you to lower the price for the van.
"THERE IS NO SUCH THING AS FOOLPROOF, BECAUSE FOOLS ARE SO DARNED INGENIOUS!" (unknown)