seattlite

I currently own a 2003 GS300, and am thinking about an upgrade to a 2006 or a 2007 GS350 with the Mark Levinson system. I have more than 100GB of music in wma lossless format, and would like it to be accessible via a personal audio device (probably a 3rd gen Zune once available, but am open to options). MP3 files just don't have enough sound in them for me. Do the newer audio systems in these cars accept wma lossless format? Are there limitations to the ML system that would keep me from having all my music (assuming a 160GB device) available? Anybody been down this road yet? Any advice or help would be appreciated. Thanks.