You need to check out the instructions at the start of the document and look at your Nav unit but my guess is that it'll be 5F000358XXA as this is the code for new Leons (5F).
In case the German is challenging here's the translation:
3.
HOW TO CHECK WHICH KIND
OF RADIO/SAT NAV YOU HAVE
4.
HOW TO IDENTIFY THE BLUETOOTH
SOFTWARE INSTALLED
WITH MY RADIO/SAT NAV
6. Notes
Bluetooth telephone compatibility
with hands-free system
MEDIA SYSTEM TOUCH / COLOR
7. DATE OF MANUFACTURE
LATER THAN MAY 27TH 2013
WITH D220 BLUETOOTH VERSION
15. DATE OF MANUFACTURE
LATER THAN SEPTEMBER 24TH 2012
WITH D210 BLUETOOTH VERSION
Bluetooth telephone compatibility
with hands-free system
MEDIA SYSTEM PLUS / NAVI SYSTEM
23. Date of manufacture
later than May 27th 2013
31. Date of manufacture
between SEPTEMBER 24th 2012
And May 27th 2013
STEP 1:
- Press the Menu button
- Select Settings
- System Information
- Check the Part No. and Software No.
STEP 2:
- If your Part No. is 5F0035858A, 5F0035846A, 5F0035834A
or 5F0035824A, go to step 3.
If your Part No. does not match any of those listed above, you
already have the latest version of Bluetooth software for your radio/
sat nav.
Keep checking this link for future updates.
STEP 3:
Check that your software version is 0407 or higher, download
the new software from the following link and follow the instructions
to install it (Link to: Instruction for updating your Media System
Touch/color).
If not, you already have the latest version of Bluetooth software.
Keep checking this link for future updates.