Simple: motor inverters are switching power in this frequency range.
It’s already below FCC limits for unintended radiation - it’s not going to block AM activity far from the vehicle, but putting the antenna in the midst of all that radiated noise is challenging.
It’s already below FCC limits for unintended radiation - it’s not going to block AM activity far from the vehicle, but putting the antenna in the midst of all that radiated noise is challenging.