Found an iPad and trying to find the owner.

I found an iPad in a rental car and want to return it to the owner. I've left it on and connected to wifi but no message has come up on the screen from find my iPhone. Could someone at an Apple store find the owner and reach out to them? I'm trying to be helpful here because I would want someone to return mine to me! I can get to the screen with the person's partial AppleID (******@yahoo.com), so I know they still have the device attached to their AppleID. Thanks for any advice on how to get this back in the owner's hands is appreciated.