Google AI answer is:
The filler cap on your Audi Q2 diesel includes a misfuelling protection mechanism (capless system) that is specifically designed to only open when a nozzle of the correct size and shape—like a standard diesel pump—is inserted.
Here is why your additive tube isn't working and how to solve it:
Why the Tube Won't Open It
Dual-Trigger Mechanism: The filler neck has two small plastic levers or "tangs" on opposite sides of the opening. The larger-diameter diesel nozzle acts as a key to push both of these triggers down simultaneously, unlocking the internal flap.
Small Diameter Tube: A thin additive tube or narrow funnel typically only hits one side or is too small to reach both triggers, meaning the mechanism stays locked.
Anti-Siphon Design: The system is designed to prevent foreign objects from entering the tank.
How to Add Your Additive
To bypass this, you need to trick the mechanism into releasing:
Use the Proper Funnel: The best method is to use a specific diesel anti-misfuelling funnel (roughly 24.5mm in diameter) that is designed for VW/Audi/Skoda vehicles.
Use the Emergency Plastic Funnel: Your Audi Q2 may have come with a small plastic funnel in the boot (sometimes located under the spare wheel cover or in the side tool compartment). This funnel is designed specifically to open this mechanism.
The "Jerry Can" Spout Method: Use a 5L or 10L plastic jerry can with a wide spout; these are often designed to trigger the mechanism.
Use Two Screwdrivers (Carefully)
