Where is the bloody navigation unit in my 2004 545i???

[inlacal]

Group,

I just picked up a 2004 545i. It has navigation and I quickly found out it didn't come with the disc....

Well...In-dash, there is a single disc CD and single disc DVD (?)

Where is the navigation unit for me to insert the Nav DVD? Ordinarily, it is in the trunks of BMW's I'm familiar with. I tried inserting the Nav DVD into the single disc DVD slot in the dash and the monitor kept saying INSERT NAVIGATION DISC....So, I'm surmising this in-dash DVD unit is not for Nav.

Please advise,
Chris