I'm sorry to say, but this video is a fake. You can't get a friend to open your car through the cell phone. Remotes work on frequencies between 302 and 434 Mhz. Cell phones operate on a huge range but no where near the range of keyless entry systems.
The FCC has made plenty of regulation to prevent manufacturers from developing systems where this could be possible. In addition, the cell phone speaker does not product radio signals - it produces sound waves. So it is ridiculous to even contemplate the idea that a friend or loved one with a spare set of keys can send the RKE signal through the cell phone to your cell phone and then activate your vehicle's keyless entry system.
We think that this myth developed around the time that onstar came out. Onstar is able to perform this trick but not in this way. Onstar is integrated with the vehicle's computer which uses it's integration with the BCM to operate the RKE system.
After posting this article we found this Mythbusters video on youtube which debunks the theory.