Can think of a few.
Living in a rural village in the back end of Devon, even in the late 90s, our village bus was one of these:
https://farm2.static.flickr.com/1444/23948889044_fca0738ab7_b.jpg (Link as not my pic; one of those 'breadvan' buses)
On one occasion, I was on the bus to town, and decided that as I was on my own and not with Mum, I would sit at the back of the bus for once. (Mum suffers from travelsickness so used to always need the front seat of the bus for any length journey) However, I was put off by the fact that the roof at the back of the bus was absolutely covered in flies. It was like a moving black carpet. It was also a different bus on the way back - as the route was run by a local coach company, it was actually one of their coaches rather than an actual bus!
My second story relates to the same bus, and, thinking about it, might explain why there were flies in the bus. As I said, my village is a rural one where one of the livestock that is around the area are pheasants. Pheasants must be one of the stupidest creatures on these fair isles (with the possible exception of EDL members), and until the local farmers realised that they could send them up the hill instead of down to where the main road was, there were countless pheasants on this road, who would often seem to wait until a vehicle was coming before deciding to cross. (I always think of quoting Douglas Adams' sperm whale here: 'What is that thing coming towards me at a great speed? I wonder if it will be friends with me?') This particular occasion a few days before Christmas, I was on the bus into town, and the driver, whenever he saw a dead pheasant that was 'usable' would stop the bus, get out, grab the bird, and put it on the floor of the bus. By the time we reached town, there were about 5 or 6 pheasants, three of which had been claimed by my fellow passengers for Christmas dinner.
Other experiences with this particular bus company include during a snowy and icy winter where our normal bus was replaced by a Land Rover with seats in the back (something like this
https://www.flickr.com/photos/k_garrett/8329670766/, again not my pic, with more seats in the back) (and I wonder whether it was actually licenced for passenger use...), and the interesting experience of being the first passenger on one of their coaches after it was back from repair from an accident. What makes that interesting is that my Mum was on that coach when it had the accident. (A Shogun 4x4's driver wasn't paying attention on a single track road and drove head first into the front of the coach; the coach had stopped.)
What also makes that latter one interesting is that I was also involved in a bus accident a few years later, a normal bus by a reputable company (First) - but it was the same driver (in all three occasions!).
I have a few more tales, but this has ended up a bit longer than I intended, so I'll leave it there for now!