They are not Effects Officers anymore but I think they are called: Assisting Officers.
It was always the commonsense approach to segregate anything which might cause distress, whether that was condoms, magazines of a certain 'flavour' or correspondence between the deceased and Miss Lita Lushbod, with whom he had struck up a 'friendship'.
I do not have any experience of the car issue outlined above but I do remember that when John Derry was killed at Farnborough, he had his car keys in his pocket.
In about 1990 the BBC had a several part programme about an accident (Friday on My Mind) where the Assisting Officer forms a relationship with the widow. The RAF 'top brass' was incensed by the imputation that such a thing would happen, however, a chap I knew quite well had done just that and eventually married the lady.
Old Duffer