(We used it as a storage closet, and never for cars.)
At some point, the drain got clogged, and half of the basin eventually got filled with urine — basically because I usually peed in the sink at night (without much light). For some reason still unknown to me to this day, I thought that the problem would miraculously fix itself. (It didn’t.)
In no time, the garage turned into a fetid sewer, so I decided to play plumber myself, and opened it up with surgical precision.
The mystery was hidden in the wall tube / trap arm and drain pipe: a muddy and very smelly substance which turned out to be urinary sediment, had accumulated over the years and totally clogged the drain. (The stuff which subsequently oozed out of the drain into my lap would traumatize me for life.)
After the urological problem was finally solved, I was severely reprimanded (despite the fact that my family members perfectly knew that I used the garage sink as a urinal), and forbidden to ever do it again. It marked the end of an era —