I was looking at the Blaupunkt RNS150 CD head unit/CD-ROM Navigation system on Crutchfield, and looked at the breakdown for the NAVTECH CD-ROMs. Boy, does Wisconsin get the hose job - the southeast 1/3 (mainly Milwaukee and Madison) gets decent coverage, but it looks like the Fox Valley (Green Bay, Appleton, Oshkosh, etc) gets "edged" (some coverage), and the western 2/3 of the state gets interstate-only coverage on a different CD-ROM. Guess I can scratch a Nav system off my list

 

May I suggest a DVD based system!
You get that whole shebang on one disc!

I have the Alpine system and it is awesome!