There was a VW Soundpack 10 speaker optional upgrade.
There are 2 speaker grills in each of your front doors - the woofer and the mid range - half way up your door.
Have a look to see if you can actually see a speaker in that mid range position, or if you can just see black cloth - this will give you an idea of if there are any units there or not.
Then put a track on and put your ear next to the middle grill - if you don't hear a speaker behind, you ain't got it!
If you are still unsure, whip the door card off!
There was also a dealer fit speaker upgrade kit:
Speaker upgrade kit - front 1K0 051 608 A
Speaker upgrade kit - rear 1K0 051 606
But I have no idea what these were or if they upgraded from 8 to 10 speakers
My understanding is that people who have upgraded with after market kit (myself included), have gone with the Focal 165 VR3