Can't find anything missing at all! The only thing that doesn't work - but hasn't worked for about a year - is that it doesn't switch off when the car is switched off.

As I say, that's not new behaviour, but has been like that for a year or more - I've replaced the AC switch due to the leaf problem, and checked the wiring, but it remains. I wonder if this blown component could have been previously damaged, and is responsible for that, rather than being a new injury?

Anyway, definitely not gonna push my luck any more today - quiet night in I think!

Thanks for all your help - my commute will be bearable again.