Sooo I am writing this article to share my experience adding a few things to my car to make it a little bit nicer. While those are no mechanical and external changes they do make it more valuable in my eyes.
I will update this article from time to time so stay tuned.
Android Head-Unit and rear cam
The first thing I did was adding an Android display to the car as the original had the lack of a navigation system and the ability to power an external amplifier. Do not quote me on this but I think the original chip got somewhere around 15 watts per speaker and the one from the unit got about 50 watts (also per speaker). That alone even made a difference in day and night for the audio quality and loudness. The original speakers aren't even overdriving that fast so you can push it quite a bit.
There are some official versions of the car radio system that at least have an inbuild navigation system but it would be twice as expensive as the one I got and limited to few things only. So I went with an Android PX5 head unit with 4GB RAM to keep it smooth. Its installation is pretty straight forward as you just need to remove the old panel and plug the cables from the new one in.
So after installing it, it was great but it did miss some customizability. Installing Hal9k Mod v3 worked great and even gave it smoother feeling navigation through the screens. After installing it I realized that I had also ordered a rear camera which needed to be connected to the head unit's wiring. - So I took it out again and connected the video cable. One thing I did not get at that time though, was that the camera had to be provided with extra power (it is a 12V camera). Luckily the included camera cable came with an extra wire for the necessary 12V connection and an extra ground cable. Connecting the 12V cable to the amplifier cable, which I will describe in more detail later, I didn't think of where to mount the camera. After trying a few spots I found that pulling the cable through at the license plate light was the way to go. So I did that and secured the camera with double sided tape for the time being (I never actually changed this as it still holds pretty well after about 7 months).
The second thing was adding a subwoofer as the inbuild audio system is already acceptable but some more bass always makes a great addition for the relatively cheap. The subwoofer chassis was already there so the last thing needed was a box to put it in which reflexes the sound but also keeps the size and costs down and is build for a similar subwoofer. I went with one from toxic as it was the cheapest one I could find which could fit the subwoofer. Subwoofer indicates we also need an amplifier as we would not get far with 50W from our head unit.
Now for the amplifier: I used the "BOSS Audio Kit" which had all necessary cables for the amplifier and even a power fuse included. For the amplifier itself I went with the Sony XMN-1004 (1000W version). Some of Sony's amplifiers even include a basic cabling kit with a fuse.
Now we needed to get some energy to the amplifier:
The easiest way to do this and not inflicting any damage to the car was to pull the 12V cable from the battery through at the drivers' door and hiding it (when possible) under the interior sheathing. To secure it I put a fuse between the battery and the cable. While doing this, both the AMP remote switch cable and subwoofer audio cable were also put under the interior sheathing so no cables are visible now.
As I do not have a replacement wheel I could use the place for it perfectly to mount the amplifier to save space - and again - not damaging anything. After connecting the ground cable to the body of the car and quickly testing whether the amplifier turns on and the box is receiving power too all could go back together.
I had two identical subwoofers in the trunk before but took one out because the difference wasn't that big and I needed the space as the trunk is small enough already without them.