Is it good manners to not move over to allow oncoming vehicles through?
Some of them sit in the middle of the road, 2 - 3 feet out from the bank, and refuse to move over to allow others through. They expect oncoming traffic to reverse, when all they have to do is put their nearside into the overhanging grass.
Maybe they should rethink their route if they are so frightened of a few minor scratches, or are incapable of reversing on a narrow lane.
I once encountered a guy in a BMW X3 who refused to reverse about 50 yards to a passing place, when I met him I had 4 other cars behind me and he had none.
I had to get out and explain to him that, unless he moved, we would be there all day.
He attempted to reverse and ended up going lock to lock into the banks on both sides. After about 5 minutes he had gone back approximately 20 yds. I got out again and offered to back his car up for him, to ease the situation, as by now several other vehicles were stacked up behind me. All I got was a load of verbal abuse.
Feck you, I thought, got back in my car and let him get on with it. Several minutes later he finally got to the passing place. I gave him a cheery thank you wave as I passed.
He was looking very flustered and I don't think his missus and kids were very impressed.
The car was on a London plate and he sounded as though he came from that way.

Similar situations, of varying degrees, happen all the time in holiday season.
It's the - "I've got an expensive new motor - so you've got to give way" - syndrome.