there is NO WAY a cell phone is going toreproduce a rf signal through the earpiece or a speaker of ANY kind.
I would suspect that when the cars remote control button is pressed in the vicinity of Cell phone #1, the signal rides the carrier wave of cell phone #1 to cell phone #2 which may or may not unlock the door. The combination of frequencys has to be just right though…a lot of the boys in the hood can get into your car at night with a cheap universal television remote by pressing Power-Enter repeatably until the car door unlocks which even bypasses the security alarm.
This phenomenon can be further demonstrated by your car radio. It occurs when you hear a Morse code type of indent coming through the car speakers and can happen just before your phone rings or if the DJ at the radio station is about to receive a call.
My Samsung phone will not trigger this indent upon receiving a call in my Ford truck or in the wifes Buick but her Motorola phone will cause the indent to be heard in both vehicals.
Another example is when my Wife leaves her cell phone on the PC desk. I give her He$$
For this because the Monitor will go all watery just before the phone rings.
The FCC used to be, (or still is) very strick on what kind of interference that a transmitting device by a manufacture is capable of causing. A prime example was in the mid 70’s and almost everyone had a Citizens Band radio. 4 watts was the max allowed by law but if you tied in a 50watt booster, you could come across peoples Stereo equipment, elect-organs, or in some cases, the extensive dental bridge-work that one may have. Other cases during this time period involved living close to a major airport. The commercial airliner might just activate your garage door opener.
You know that the cell phone carrier wave is more powerful than this, but again is on a different frequency.
In closing I would say that Some of the Phones will unlock some of the vehicals but it is far from being universal as claimed. The interferance that the remote causes to the cell phone carrier is going to be weak so cell phone #2 is going to have to be close (within one foot) of the door lock recieving unit.
I find this interesting just because of the possibilitys, with free weekend minuets or free person to person that subscribe to the same company, one could possibly activate an electronic predator caller without worrying about brush interferance or distance by using the cell phones.
