Need Navigation Disc
 

Ok, so I ran a search and though I'm sure this ? has been asked, I couldn't locate the answer. I just bought my wife a '05 4.4 E53 to replace her 335i. The X has nav, but was missing the disc. The dealer (non BMW) promised to get us one, but my previous used car experience tells me that I may be waiting in vain.

Can anyone tell me how to get one cheap or free? I'm a bit hesitant to get one off the internet unless it came through a trusted community such as this. I could of course trade my oldest son for one at the stealership, but he's starting to grow on me and would like to avoid it if possible... ;)

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