Laz,
Let’s consider for a moment who might have left it behind, and under what circumstances it was left behind.
Keep in mind this car was rented AT AN AIRPORT!!!!!!
The soft case itself is a bit indiscreet in that environment.
I’m betting the owner already weighed the risks of retrieval and would not respond to any outreach.
And, if he did, you wouldn’t want to be there to present it to him.
Well, in that case, I would have a new firearm.
AW HELL, no I don't, it JUST went overboard in a tragic boating accident!