I got myself into a very well-known situation. You own a 3D printer, look for the needed model to print, and cannot find the one that suits your needs. The solution is simple - you design your own.
I designed an armrest tray/organizer that ideally fits the Hyundai i30 N (probably non-N models too) pre-facelift models (MY2017-MY2020). Not sure about the facelift models, since they got new seats and might have slightly different armrest box shape or size.
Recommend printing it in multicolor using PETG. Not much waste for the multicolor print, but it adds quite some eye-candy. Supports are needed for the side lips.