Please elaborate as to how the fob or car would detect the MITM:
1. You place device A near car and device B near fob.
2. Device A relays all Rf transmissions in the target frequency range(s) to device B, which rebroadcasts, and vice versa.
Public-key encryption / authentication only ensures that no-one in the middle is reading or editing your connection. It does not prevent someone from relaying your communication. (And a good thing too, else the entire encrypted web wouldn't work.)
1. You place device A near car and device B near fob. 2. Device A relays all Rf transmissions in the target frequency range(s) to device B, which rebroadcasts, and vice versa.
Public-key encryption / authentication only ensures that no-one in the middle is reading or editing your connection. It does not prevent someone from relaying your communication. (And a good thing too, else the entire encrypted web wouldn't work.)