You have the latest version. The "4-1/00" indicates that you have a MKIV with OS version 10.0. The version display convention loses the "1," because it does not have enough digits. MKIV nav OS 10.0 was included on both the V31 and V32 OS release CDs.

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SOLD
2000 E38 750iL Highline Edition, Upgraded with the lastest 2006 X5 Electronics
MKIV Navigation, 16:9 Display, Bluetooth, TV/Video with Backup Camera, Sirius, and Aux Input