Will a car fail an MOT test if its rear windscreen wiper spray nozzle doesn't work?

Could be. Do you have a rear screen washer? Maybe the pipe involved is disconnected or damaged and is piddling screenwash fluid into the boot.

That would account for both the damp and the smell.

I cant really gove you an answer,but what I can give you is a way to a solution, that is you have to find the anglde that you relate to or peaks your interest. A good paper is one that people get drawn into because it reaches them ln some way.As for me WW11 to me, I think of the holocaust and the effect it had on the survivors, their families and those who stood by and did nothing until it was too late.