Ok, so it finally happened.
I left my car on a parking lot and when I came back I had one nice scratch on the lower side of both doors and another one a bit higher above the rear wheel (which is also a very slight bump, but not really deep so I'm willing to live with that). The lower one is probably from a bumper and the upper one probably from a side mirror.
I took the truck to a friend of mine and he managed to polished most of it out.
Can anybody recommend a good way to get the scratches out of the paint? They are only very thin and not deep, but deep enough to make them look white and, of course, visible to me even if not to others.