Yes, it can be done with range extenders, though it requires high technical skills. But still it can be done. Car theft in western countries is actually higher with keyfobs than traditional immobilizer+key. Since push start is getting common here, I think thieves will buy such range extenders from black market soon if they haven't already.
Watch this video to see what I am talking about:
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For peace of mind you can buy RFID Signal Blocking Pouch for your keyfob as shown below. I haven't found it in Pakistan yet, so I am thinking about importing one. If you know where to get it then let me know.
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