Here's my *useful* reception range including the fringe areas with a Sony ICF-38. Daytime only. My house is marked. Nighttime is reduced to just my block. Or less. Also included a picture of this readily available radio....one of the last better than average portables made. I have a few of these. 
I assume that's outside. What does a car radio give you?
I assume that's outside. What does a car radio give you?
Yes outside. The car I have now, a Kia Forte, isn't as good as my Chev. Cobalt was with a fender antenna and no computer screen and other electronics. With the Kia weaker stations that should be clear and perfectly listenable like in the Chevy are obliterated by the electronics of the screen and other things. It's like a hum that wipes out the weak stations. So what I did was drive around.....could have walked but that's a lot of ground to cover....and stopped at different locations with the portable that actually is better than the car for the reasons I mentioned and got out and checked. Did it like this to map out the general receiving area. Including the fringe where it can barely be heard. Cars used to have a radio enclosed in a steel case, removable, and the antenna was also grounded with the case and fender mounted. There was noise suppressors and spark plugs called resistor spark plugs. Now the newer cars have the radio incorporated with the audio/video screen and it's array of electronics and AM suffers except for strong signals. If I shut the car off and wait 3 minutes some electronics shut down and it's better but still to get the fringe areas the portable was better. Eliminate the car's electronics and the car reception would be best like the chevy was.
Distance isn't as impressive as it looks in picture and you can see at the bottom the scale for 100 meters.
Again, a clear demonstration of how useless range measurements are when using a car. Cars and their radios vary greatly.
Kias are especially known for having poor AM reception. When I first put my station on the air a coworker with a Kia could barely hear it two block away, I had solid reception in a Ford Escape out to nearly two miles. That was a 2010 Escape before the days of fancy screens and all the other electronic goodies.
However my 2021 Ford Bronco Sport with all the electronic stuff in it that I think has been invented so far can also pick up my station solid to the same spot as the old Escape. It's not so much a matter of the fact that the electronics are in the car, it's how well it's all designed I suspect. My wife's 2018 Escape and my Daughters 2015 all receive the station equally well.
Our 1953 Mercury with an after-market radio literally a Kmart radio (Kmart brand name even) does not pick up as far as the 2021 Ford. It has a 1970 Mustang 351 in it with old school ignition, or course with resistor plugs and ignition wires, and an antenna mounted on the fender. Don't hear any interference, it's just not all that sensitive.
Virtually every car on the road has resistor spark plugs and suppression style wires. You would have to go out of your way to purchase non-resistor plugs these days. Non resistor and no suppression ignition components are pretty much reduced to use in racing applications these days. Without suppressed plugs and wires all those computers in the car would be horribly screwed up by all the rfi interference.
TIB