Could be RF interference. There is a ton of RF energy floating around, especially in urban areas and along roads. RF interference wouldn’t be hard to prove one way or the other, though. Half an afternoon with Toyota, a signal generator and PA and I could determine fairly conclusively whether or not RF was the culprit.
This is of no danger to anyone, but a friend of mine has a 2 year old Caddy. When she parks her car on the North side of the local JCPenney store her remote door locks will not work. If she parks on the east side they work fine. The problem only happens there and can be duplicated each and every time. The service dept can duplicate the problem at that location but no where else. The only thing they have come up with as a possibility is the RFID transceiver at JCPenney. Her answer is “just park on the east”.