Either dodge chargers in your area don't have the loud exhausts that they do here in California, or you have a problem of some sort. Loud noises bounce off the road, off buildings. Basically the reason you can hear someone talking yell even if they are facing away from you.

Maybe it's because I rarely drive in cities where there are buildings around for the sound to echo. 95% or more of my driving is in the country at 45 MPH or higher, or on highways at 65 or 70MPH. There are plenty of very loud vehicles in my area. Maybe the sound just can't go as fast as I'm usually driving. Or an idea I just thought of, maybe at the speeds I typically drive, by the time the sound does get to me, it's not enough to hear over my tires?

Yes, obviously the danger of getting passed by a much faster silent vehicle is much less in an area with low traffic density, low intersection density, yada yada. I'm glad we finally got to the bottom of your confusion.

We didn't though.

Edit: Also I feel like, from your last reply, that you might have taken one or both of my replies in a way that wasn't intended. It's also possible that I didn't word my replies in a good manner. I'm not always good at that. I am genuinely curious about how it is that others can hear loud vehicles behind them when driving while I can't. Your mention of echoes off buildings got me thinking of driving through a big city surrounded by big buildings, and that's an environment I am not familiar with except in pictures and videos. If that's the reason then it answers the question I've had for a couple years now when I first saw someone mention that they hear loud vehicles behind them.