I looked into this same kit for my ‘07 5, and the price tag had me questioning it.
What I did instead? AliExpress. Found a 2DIN Aux connection with a male 3.5mm plug (another w/female 3.5mm for the aesthetic option). Installed the one with the male plug into my stock head unit and ran the cable out just south of my gear shift.
if you don’t have stock nav, there should be an available port on the head unit that will allow you to use your “AUX” button with either of these cables.
Works like a charm - cost less than $10 for both options.
One like this is what I’m currently using.
Smarter Shopping, Better Living! Aliexpress.com
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