RCD510 Many Bluetooth & SD reader questions

Hi All,
As you can see I am new and this is my first post.
My wife just bought herself a 2010 Golf 6 Comfortline, it came with a RCD510 headunit and fancy steering wheel buttons.

The bluetooth function is always greyed out, so there is no way to do anything with it. I have looked under the seats and there is no bluetooth box (perhaps it was nicked?) and no sign of the end of the harness.
I have tried finding it with my iPhone SE and a very old Nokia I bought back at the start of 2010, but there are no devices available.
Is it possible the bluetooth unit is built in\or behind the headunit?
If not, and I need to install a new Bluetooth unit does anyone have any info on running the cables all the way to under the seats or is it possible to have a bluetooth unit directly plugged into the back of the headunit?
What Bluetooth unit do I need? I have seen many references to an 9w7.

Also in the car there was an SD card with bad (not our taste) music, however when I have put better music on the SD card the headunit does not recognise the SD card - I have formatted the SD card to FAT32 and NTFS but without luck.

Is it possible to swap out the 3.5mm jack input for USB?


Any ideas?

Cheers.

I'm having the same issue with my golf 2.0 tdi 2009. No bt module under the seat. The sd card sometimes gives errors. I tried to clean the folders from any bad mp3 file. Some mp3 files were talking ages to fully read even with windows so i got rid of them. But there are still reading problems. I think there are more mp3 which are not properly set.

Sent from my SM-G935F using Tapatalk

I trashed the stock headunit and slipped a pioneer in it's place. Has carplay/android auto and built in bluetooth. Kept the steering wheel buttons as well.

Excellent upgrade for 500 bucks imho.

ymmv