I just did a key reprogram for a new key and read somewhere as I was researching how to do it that the receiver is in/at/part of the rear window antenna system.

Actually, as I write this I remember it was a you tube video. Guy said if you were having problems reprogramming your keys, to hold it over your shoulder because the receiver was in the trunk window, or tailgate. RealOEM shows part number 65248382450, “antenna” back there as part of the radio system, but I wonder if it does double duty?

__________________
Current
Original owner 2002 E53 X5 4.4i to 4.6i swap
2026 G80 M3 6 spd
2025 G06 X5 50e
Former
1972 Audi Fox
1986 Saab 900S
1996 BMW Z3
1998 BMW E36 M3 Sedan
2004 BMW E46 M3
2006 Audi A3 Quatro
1993 Mopar 318 Jeep Grand Cherokee
2015 V6 Jeep Grand Cherokee