I clipped my wing mirror backing into my garage once. Took a bit of casing with it and put a small dent in the side of the garage, that's about it really.
I've done a few minor things that haven't resulted in any damage.
Going through a tunnel of cars, a bus failed to give way (I had nowhere to go and was already a good distance through the make-shift tunnel), we both come to a stop about 3/4 the way through, I slowly inch my way down the side of the bus, being careful not to scrape it, but I neglected to consider the left side and dragged my mirror a few cm down the window of parked car (Maybe dragged is a bit too strong, it wasn't even enough to fold my mirror in). From there, I let the c*nt of a bus driver do his thing, knowing that if I were to move much further, I'd end up clipping the wing mirror of the car I had already contacted. Was gonna stop and look for damage, but by the time I was at a spot that was safe to pull over (which would've been at the end of the 'tunnel' and then a decent bit down a side road), I had completely forgot which car I had contacted. From what I was looking at during the moment, there didn't seem to be any visible damage, so I didn't take it any further. If it were my car that was parked, and there was no damage, whatever, I'd let that slide.
Then another time I did something that... Honestly, I really don't understand how I did it. But I was driving to the nearest co-op while on my break, and on the way there, there was some road works, the sign on my side of the road was flat on the floor, faced down, I didn't see it at all. Slowed down to give way to a bus coming through the same tunnel of cars mentioned above, and as I got down to about 15 MPH or so... *jolt* *Thud* *jolt* *Thud*. If it wasn't obvious, I ran it over. Like I said, it was flat on the floor, face down (back side facing up), I didn't see it, how? Idk. When I was closer I would've been more focused on the tunnel of cars and what was coming down. But even coming up to, not once did I see the sign on the floor. Much like the previous one, no damage. Well, not any that I've noticed, maybe some scratches on the lower bits of the body work? But with it being a black car, you don't tend to notice light scratches.