Case of the Unlocked Trunk

....or where is Nancy Drew when you need her? Are there still Nancy Drew books being printed?

Victim: 2001 Hyundai Sonata
Crime: A trunk that keeps opening. Twice the trunk was open long enough to kill the battery because the light was burning all night.
Suspects:
#1- Neighbor's new car. This started several days after she got her new car, a sporty silver Nissan. Could her locking system work on the same frequency as our car?
#2- Transmissions from circling aircraft. We are located under the flight plan for Philadelphia International Airport. I've heard that garage doors and gas fireplaces may be affected by those planes. Could it happen to car trunks too?
#3-Alien spacecraft communicating with our car? For what reason? Probably unlikely.
#4-Recently developed site of a new "Bermuda Triangle", located in a 6 foot diameter circle in our driveway. These electrical problems do not extend to the locking system or engine, but the retractable antenna in the trunk does not always extend fully. Probably not very likely either, how disappointing!
We have temporary remedied the problem by deactivating the electric lock and just using a key. How 20th cedntury.