Not sure about the 7/03 date you mention, but the BM53 Radio I am selling on Ebay right now (5/2004) does exactly what you want. Split screen radio/nav and Nav instructions doesn't completely mute the radio. Also the radio is compatible with Aux input and Sirius Satellite Radio.

Cheers, Adrian

http://cgi.ebay.com/ebaymotors/BMW-B...spagenameZWDVW