Someone reversed straight out in front of me in the supermarket car park this morning, I was not going fast and they probably assumed I had seen they were about to move, but they had no reversing lights working and it scared me to death! Would be even worse in the dark somwhere.
Also I am astounded by how many people I see with only one brake light working - if its someone I know or they've parked and I can speak to them I always tell them.
Please, everyone, remember to check all your vehicles bulbs regularly. Carry spares and know how to replace them.
Don't get me started on people who have working indicators but forget to use them LOL!