I know this is a shortwave forum, but I suspect some of you can shed some
light on this issue. It falls under the heading of "things I can't fix, but
I'm curious anyway".

I'm in Rochester NY. A local rock station, WCMF 96.5, bills itself as having
the most powerful signal in the region. Indeed. It's so powerful that it's
actually distorted when I listen on my car radio. "Like fingernails on a
blackboard" is the most accurate description. Even the voices of the DJs are
distorted, almost like listening to someone who's got phlegm in their
throat, but hasn't cleared it yet. The car radio in question is a stock unit
in a 2002 Toyota Tacoma. I think Panasonic is the mfr. All other stations
sound nice & clean.

Assuming for the moment that the radio isn't at fault, why on earth would a
radio station run their equipment this way?