I was going under a single-lane low bridge behind a builder's flat-bed lorry. The guys in the lorry thought they would have some fun with me and threw their empty plastic coffee cups out of their windows.
Cursing quietly to myself I managed to dodge the cups. We emerged on the other side and the lorry guys were too busy watching my progress that they failed to notice an oncoming lorry and smashed their side-mirror to pieces!
I didn't mind dodging the broken mirror and I gave them a toot on my air-horn as I took the next left.