Volkswagen Polo 2009 bluetooth problem

Based on my experience with my 2009 Skoda Octavia and its Bolero head unit (different model but probably only cosmetic differences), as best I remember the Bluetooth option remains visible but greyed out in the entertainment system setup menu even if the car is not fitted with a Bluetooth module and the functions cannot be accessed. Pressing the hardware Phone button when no module is installed just muted the radio in that case.

You really need to determine if a module is actually fitted.

One method would be to find out where it should be located and see if it is actually where it should be. They are separate from the rest of the entertainment system and they are quite bulky and often located in a polystyrene housing when fitted in the OEM position (see image below). Although this isn't fool-proof as it is common for them to be located in the wrong place if retro-fitted as a DIY upgrade. For example, when I fitted my module myself I ended up placing it behind the glovebox rather than under the passenger seat where the factory would have fitted it as there was (only slightly) less pulling the car interior apart to route cabling.

Additionally, if the module is physically there and wired in then it also needs to be enabled in the car's CAN bus controller or the car will not know to look for it. You will need a garage or someone friendly with a tool like VCDS that can check this for you but it is quite simple to check.

Last thing to add, again from experience, there are many subtle variations of these modules available and they are not all fully compatible so if it has been fitted as a retro-fit with a slightly wrong version then it might be possible that the module is there, wired up and enabled in the CAN bus but you are not able to use it because you cannot pair your phone. A little story to illustrate - when I did my upgrade I initially bought a better featured module that I didn't realise needed the car to have a Maxi-Dot dash-pod display and multi-function steering wheel in order to pair with a phone, neither of which my car had. Fortunately I was able to plug it into a friends car to do the pairing and it worked fine when the module was moved back in my car afterwards, up until I upgraded my phone. My friend had sold his car so I ended up having to replace the module with an effective downgrade in order to pair my new phone.

Hope this helps. Can't help with the Aux jack location for a Polo though I am afraid!