Which cavity hides behind this stopper

Golf6 1.6 – Mod. 2009 Hello all, I have already posted this in the model forum. But since I am in a bit of a hurry, I ask you again here. Could be good that one of you has already got a Golf 6 under your fingers. So, it’s about: I want to use Fluid Film to treat my sleepers/wells. Now I have found a 3rd row of plugs, which are partly under the floor cover. (see picture) I would like to know which H So far I thought that I only had to supply the outer and the adjacent threshold. Thank you very much! Addendum: I just got the information that the fuel line runs there on the side of the passenger. Should this cavity and the line be sprayed with FF there?