Annoyingly, the seller wrote something on the face of the radio (whyyyyy?!) and the knobs were rather... slimy.
Fortunately both issues could be solved with Orange cleaner (Liqui Moly 21467, really good stuff).
Unfortunately however, one of the plastic clips of the cupholder was broken, which means that it flopped around quite a bit.
This is how it's supposed to look like:
Simply gluing the cup holder to the metal bracket was not really an option because I don't think it would last very long. So I drew up a sketch in Fusion 360 of a repair solution. Making functional clips with 3D printing can be rather challenging and they often break easily, so that was not an option. Instead I made a two-part solution with a screw:
The lower part of the repair patch is glued in with some strong Pattex contact glue. Since I couldn't clamp it while the glue dried, a creative washer was utilized
Once the glue was dry, the repair patch was assembled and now everything is as strong as it was supposed to be
Usually it's not optimal to screw directly into the plastic, because it has a tendency to creep over time (even though ABS is not as susceptible to that as PLA), but it was all I had on hand right now and I wanted to get the repair done.
Unfortunately, the radio does not fully work. Both speakers on the right side don't work (the speakers are fine). It does not appear to be a configuration issue, since I reset the radio to factory default in the hidden menu and the "Fader/Bal" knob does not help either (but does that button actually influence right-left balance? The manual says it does, but in my S60 with the HU-603 it sounds like it just affects front-rear).
Oh well, I'll see if I can find another radio for cheap, so I can swap it again. Probably only the amplifier chip of the radio for the right side is broken, but I don't know if I want to dig into it to repair it...






