1 - It is not necessary, but to be totally safe, wait until the MKIII totally powers down, and the LED turns off. Then disconnect the battery. Do the swap, and then reconnect the battery. All that said, I have done several nav swaps without disconnecting the battery. The key is to make sure that the MKIII has fully shut itself off.

2 - Nope, you can turn on the car right away.

3 - Your nav CD is fine. No need to wait until you get the DVD. Of course, you get lots more function and information from a DVD, when you eventually get it.

4 - Sure, as soon as you do the swap, put in your map disk (CD or DVD) and you are immediately off and running.

5 - Just go for it. You can do the SW update right away.

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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