Are they in the right position? They should click in place.

Hope you will notice your car's missing before that

An easy way to protect your car against thieves or just to keep an eye on it, when you're not the one who's using it. Like when you bring it in for maintenance. Or just to find it rapidly on big parking lots. As I'm an iPhone user, I use the Airtag, but I also speak about the options for Android use...

Please share some pictures.
I would insulate the back of the battery as well to avoid contact with the aluminium case.

+1
I always charge heavily when travelling (the wife loves to bring EVERYTHING with her ) and sometimes indeed, something blocks the door lock.
You should be able to feel and see the difference but you know for sure when you lock and it goes like "beep beep - beep beep".

Could it be someting like an antenna?

Never seen this before. Maybe due to the heat and the reaction of the different materials. The leather/sky part shrinks a bit more than the plastic I guess?

Great! But still connected upfront as before? So you'll especially have airflow in the back when you select airflow to the feet in the A/C unit, correct?
Maybe you could re-use a part of the under seat vents to connect it to the official outlet in the front and connect it this way to the back.

Wow, what a commitment :) With the plastic part they use it just slides over so it would be quite easy no? There seems to be place underneath as I guess that the relays go just in front. It also explains why I never spotted it before on Dasaita install videos, the metal bracket was hiding it... Also...

Well as I read you're looking more for a plug & play solution rather than modifying electrics in order to stay as "from fabric" as possible. But know that the 3d party solutions are plug & play and that there are loads of tutorials online to be found, while the Connect 4 isn't comp...