Its a 2002 C230K Coupe.  Basic symptom is bad static over the radio
when the rear window defogger is engaged.

Dealership claims that its an expensive repair...basically have to
replace the entire rear window and something else?   Sorry, can't
recall the basic details, other than some comment that sounded like
they were alluding to crosstalk interferance between the radio antenna
that's in the rear window glass and the defogger's wiring.

While I'm no EE, I would suspect that it is either an intermittant
connection someplace, or a switch relay that's going bad and making
noise.  I find it a bit hard to believe that the glass would have to
be entirely replaced, unless there was some obvious damage to it
somewhere.

-hh