Sponge tray that can be magnetically attached to the inside of the sink. In this way, residual water drips directly into the sink and, despite the holder, the full size of the sink is always available when needed.
The tray is designed so that residual water can drain through several rounded drain holes. All internal edges of the tray are rounded to allow easy cleaning.
Remember that a stainless steel sink is not magnetic and magnetic washers, for example, or preferably magnets with different polarity must be glued to the outside.
I recommend using heat-stable filament such as PETG, ASA or ABS, as PLA loses its shape in the summer months in a warm car. A layer height of 0.2 mm with a filling of 20 % have proven to be very stable.
Two, preferably four strong magnets and corresponding M3 countersunk screws with nuts (stainless) are required for mounting.