Can anyone tell me whether the so-called
"Bose Premium Stereo System" included in the 2000 E320's E2 package (with rain-sensing wipers and moonroof) differs from the standard radio ONLY in that it uses different, presumably better (Bose) speakers? Or is it the case that the AM/FM cassette unit in the "Bose Premium Stereo" package is also different (and better) than the standard radio unit?

Many thanks if anyone can clear this up for me.

Robert