Snopes Remote Possibility (haha)
Here’s what snopes has to say about the Remote Possibility
“(More than a few people have inadvertently fooled themselves into believing the cell phone method of unlocking car doors actually works because they tried it and achieved the desired results — not realizing their cars were still within range of their keyless remote devices, and the signals that unlocked the doors were transmitted the usual way [i.e., through the air], not via cellular phone connections.) “