These are another case where the sound engineering principle of KISS is forgotten. First introduce a more complex solution, find that it's broken, then keep adding more and more layers of complexity in the hardware, software and protocol to try to patch the problems that the initial complex solution introduced.

Meanwhile, my Honda has a physical key without a transmitter and the car has no receiver. There's nothing to intercept and I can go swimming with the key with no ill effect. No batteries to replace and if I need a new key it's $5, not $400. It's a brilliantly simple solution!