I drive an EV, which are the cars where AM radio supposedly has the worst noise problems. The AM radio works fine in it -- not any worse (or any better) than the AM reception in the last fully gas-powered car that I drove. For that matter, the AM radio also worked fine in my previous vehicle, which was a range-extended hybrid that would also supposedly have the noise problems.As I understand it, to make AM work well in modern cars, it takes a lot of noise reduction, RFI reduction from car computer systems, etc.
The issue that car manufacturers have is that sure they could include AM radio, but it wouldn't work very well.
Same goes with AM/FM in cell phones.
At home, I can barely hear local AM stations at home on my desk because of all my computer and electronic gear overloading it with RFI. (It's true I'm an outlier and most people don't have as much digital gear on their desks as I do, heh!)
So simply enabling a chip feature alone doesn't solve the problem.
That being said, with more receivers moving to a SDR approach, you can do a lot more filtering of noise and cleaning the audio. But that's going to cost money too.
This seems to be about the desire of some manufacturers who wish to save a couple bucks on a filter that is needed to make AM radio usable in their vehicles. And for context, Tesla deleted a temperature sensor from their vehicles that probably cost somewhere around 40 cents at quantity. (For those who don't want to click on unfamiliar links, the link is to an example IC from TI as priced by Mouser Electronics)
And while I certainly understand the desire of manufacturers to save a buck, it is also reasonable to note that there is an actual public interest (due to the EAS system) in maintaining support for AM radio reception. A few pages back, David noted that few people own a battery-powered radio anymore, so I'll note that the radios in our cars are the closest thing that many people have to such a device. And, yes, in an emergency people could go to their cars and listen to that radio for information when everything else is out.