Mandating features at no cost to customers is like trying to argue with math. They aren't going to sell the cars at a loss. They'll just raise all vehicles by the cost of the radios, and it'll be impossible to prove without line item pricing.
One which consumers likely won't buy.
They don't care if the sticker price goes up by the cost of the am radio. They care that manufacturers install it, and don't make it optional.
And they don't care because it's like $5 worth of parts (honestly probably less).
Can they produce a car which includes a radio that is practically useless because the vehicle gives off so much electric noise?
Gosh if only there was some sort of widely distributed network with transmitters all over the place that could get information to portable devices that people carried with them at all times and which can be woken up remotely even if they're otherwise asleep/turned off, we wouldn't need to push this obsolete century-old technology with a vague justification of "emergencies".