I don't want to be dishonest, or start a flame war, but IMHO this will not solve the problem.
In my view, this ""solution"" will lead to a more complicated feature with more energy consumption for nothing. IMHO, these ideas are all about to not to solve the problem itself, but to let they sell something as a feature, while this way will be able to deny the bug itself.
IMHO, if you are moving, then the key will be on, and it will always happen if you will walk, you will drink and feel yourself good in a bar, or in a disco, or in a shopping mall, so a theif could steal your car without any problem.
I think, we have to see this problem from the right angle: As long as you have to press the button on the door to lock it, so you will always have to have a free hand to turn something off or on in your pocket. But this solution could be very easy, simple, and cheap - so they will not install a 0,1 Penny swithc into it, when they can sell the new, featured advanced, hyperturbo, 3D orgasm advanced "almost unstealable" and more expensive key - for which they can sell the Faraday pouch immediately.
However, if the customers wants that feeling, to have a more-and-more advanced key, which is almost solves the problem, and will be more and more comfortable while nobody cares that the original bug will be the same, then yes, this thinking will continiue, and we will all forget about the very simple and cheap solutions. Which are in the other hand are more safer then the high-tech almost perfect solutions. That's reminds me the Titanic's original brochures, which called the ship as "practically unsincable", and from which the "practically" world was lost in space almost immediately.
If you look for that solution, you mentioned, then you will clearly see, that it works only
when you put your key down for a long term, which means, you have to put the key in your hand, you have to move it down to somewhere, so it's impossible, that you can't turn a swith off with your empty hand.
But it's my opinion, and I think, somehow I will install a switch into my key as I don't want to pull out the battery all the evening.
Have a good night
