That is really good advice!
I have an old car, and it's easy to unlock most older car trunks from inside: find the lump that is the inside of the lock, stick your finger in the (usually square) hole, and move that little bar (less than a 1/2" long) whichever way it will go, and the trunk will pop open.
However, the locks on the new cars are covered with carpeting. Is that hole still there, under the carpeting? I would like to know, but everyone I know drives a Jeep, pickup or van.
If someone wouldn't mind, and has an actual car, could you stick a heavy needle around the inside of the lock and feel for it? If there is one there, I would cut the carpeting from over that hole and tell your family about it.
I learned this trick when I was driving limo in Las Vegas. Some of our passengers were scary, and one of the drivers said you could do this if you ever got shoved into it (lots of dead bodies are found in the desert surrounding town). Later that day, we were waiting at the airport and nothing was moving, so I asked a driver I trusted to stand outside the limo with the key to make sure I could get out. I crawled into the trunk, she closed and locked it, and I felt around in the dark for that little hole, moved the bar, and the trunk opened. So she climbed in and I was outside, and she opened it, too. Then I got a call from my dispatcher: "One-twelve, WHAT are you DOING???" (Innocent voice: "Nothing. Why do you ask?")
Sue