Which SD card gps for 2019 C300

[Michael J Tallen]

I have 2019 C300 no GPS. I have bought 4 different SD cards off EBay and none worked. I have wide screen but says I need audio 20. How do I know if I have audio 20? I hate dealer so if you know which numbered card I need. I love you.
I do use Car Play but my new $1200 iPhone is broken now and I need gps.

 

[Srdl]

I have replied to your other thread

 

[Blobcat]

Likewise