[Myrddin]

Electric motors put out broadband RF noise that can wipe out AM reception. Fixing that problem is expensive. Deleting the AM radio dodges fixing the problem by removing the affected component. Old gasoline cars with a distributor and mechanical points put out some level of RF interference that could obscure a weak AM signal. Alternators insert "whine" on the DC system of a car. That can be filtered at a small cost. People who purchased cheap CB radios often had to purchase power filters to eliminate the alternator whine.

I was sent to a small fishing boat in the late 70s. His emergency radio reception was being completely wiped out by the onboard alternators providing AC power for equipment. I tried to convince him that the problem needed to be fixed before he took the boat to sea. Too expensive. He went to sea, had problems. Called for help on that radio. Didn't matter because he couldn't hear anything. The boat sunk. He died. RFI is a real problem.

[Flying Circus]

They can restore the AM radio band with a software update. Maybe it doesn’t work as well if they didn’t put enough shielding or filtering in but activating it in software tells us that there is something other than cost driving the decision to remove it.

As far as the cost of noise filtering, I would think all computer and communication systems in the vehicle would benefit from have good power filtration to protect from the electric motors’ noise. Given the average cost of a new vehicle is north of $40k, $100 for noise filtration seems trivial.