From Tech Page One website...
"Recently I acquired a new car, the first in 14 years. It was a Chevrolet Volt, with cutting-edge hybrid technology and a Car of the Year award in 2012, but the agent who sold it to me seemed impressed most of all with its “smart key.” Since I misplace my car keys often, a smart key conjured up visions of something that would come running when called. Sadly, that was not what it was. It was interesting nonetheless: a tiny electronic gizmo that remotely spoke to the car.
This meant that things I had done for my whole life without complaint or even an inkling that they were burdensome were now eliminated. No more tiresome inserting-key-into-ignition-and-turning, for instance. I could simply push a button to start the car if the smart key was nearby. No more fishing around in my bags or unsightly pocket-patting to find the old key fob. Within three feet of the doors, the smart key automatically unlocked the car. “Neat,” I said.
Soon after, I went surfing. I usually take my key with me in my wetsuit. Belatedly it occurred to me: a smart key is not waterproof. What to do? Hide it on my car? That wasn’t feasible, as it meant the car would automatically unlock, even when the key stayed hidden. Call a locksmith to make a door key and hide the smart key inside the car? Nope. Still within three feet. Then I had an epiphany: metal would interrupt the transmitter! I searched at local hardware stores and on the internet, but the lockboxes and magnetic key holders were all plastic. I bought a thick, albeit plastic lockbox. The doors still opened."
Read the rest here: http://techpageone.dell.com/tech-culture/smart-key-pretty-dumb/
This issue is faced quite often while traveling and hiring a car and getting the similar issues.Then the person is left with no other solution except searching for a locksmith nearby.
I think wrapping it in aluminium foil before putting it in the lock box might work as it should reflect the (presumably) infra red signal.
Another option is to take it with you. I put my smart key in an Aquapac and attach it to the loop in my boardshorts. I’ve used it surfing and bodysurfing and never had any issues.
I used a surf lock for about 5years until I inadvertently left it beside my car after a surf. I then purchased without any research an O + E super strong key safe. It was as stated super strong however it has push buttons not tumblers. The problem with push buttons is that the code numbers can be entered in any order as the mechanism recognises the numbers not the order they were entered.
I then did my research found this article and comments, went to the locksmith and got a door only key cut for $15. I now either use a lanyard when wearing a wettie or use the the key fob of my leggie.
Much more secure than any key safe. Even if u hide the key somewhere on ur car the car can't be stolen as the key won't start the car.