I think you’re not understanding the attack. It could be a unique, unpredictable signal every single time and the relay attack would work just fine. The devices

I think you’re not understanding the attack. It could be a unique, unpredictable signal every single time and the relay attack would work just fine. The devices intend to use distance to prevent this, with distance determined by strength of signal. The relay captures the challenge, passes it to the fob and then passes the response back to the car, boosting the signal if necessary. The timing on this is fast enough that it is within the tolerance of the system. As long as these devices are acting as proximity sensors and your fob isn’t electromagnetically isolated, this attack will work. No amount of key rotation will help.