For anybody whom owns a Renault Kadjar and has the Keyless KeyFob (key card) option, the Kadjar via it Control Panel has the option to disable Hands Free Key Functions.
This is essence Allows the keycard to be used again as an actual key fob to unlock doors and boot via the push of a button on the keycard and the option to allow the door to automatically be unlocked by pressing the door lock is disabled even if the keycard is in range, thus help preventing the wireless relay attack to gain entry in the Kadjar.
Alas this still does not stop the wireless key card from broadcasting a constant signal, but at least to get into the vehicle, will probable set off the alarm etc.
Also if the car thief using the relay attack method and cannot open the vehicle door, then this may deter them further
A Faraday key box to store the keys overnight is the best way to reduce this risk, but we have all at some point left our keys in our coat pockets after a challenging day at work
In a completely sane world, madness is the only freedom (J.G.Ballard).