Smartfobs, relay attacks and latency being the 'defence'??
Is this possible to be classed as security through obscurity - in a loose sense?
I'm a total hater of auto unlocking vehicles if the fob/gadget is within a certain distance.
A friend of mine had a Beemer, which would auto-unlock when the keyfob got into proximity. Therein lay the problem.
Drive forward into parking space
Walk to boot, open boot.
Go inside the house....
Go back out to move bins for tomorrow.
Car unlocked, and you didn't know... because the bins were at the same range.
It happened numerous times. A lot of the time he giveaway was that the wing mirrors had gone into normal position rather than folded - if you saw them.
There is a price to pay for convenience, and it is a big one when it cost £40K plus!!