If you want the police to help you in the current climate, you've got to be seen to be taken every precaution.
This would show two things :-
The owner is who he says he or she is.
If he's not the police will with the photo and it will assist in a claim if you've been the victim of a fraudster!
Finally, cars which have been flooded, have a history of being as good as impossible to cure (there intermittent faults and wiring bugs means NO RELIABILTY.