I was relieved to learn that nothing was wrong with the car. There was no damage to the paint, no scratches, and nothing permanent. After giving it a proper wash, every single mark disappeared without leaving a trace. What I had mistaken for damage turned out to be nothing more than harmless snail trails.
Looking back, it's funny how quickly our minds jump to the worst conclusions when we see something unfamiliar. If I hadn't asked other people, I probably would have continued worrying or even taken the car in for an inspection. Instead, I learned something new that I never knew before.
So if you ever walk outside one morning and notice strange marks covering your car, don't panic immediately. If your car was parked near grass, bushes, trees, or anywhere damp overnight, there's a good chance a few snails simply wandered across it while you were sleeping. A quick wash is usually all it takes to make the marks disappear completely.
I never imagined that such a simple explanation could solve something that looked so strange, but now I'll definitely recognize those marks if I ever see them again.