Welcome to the forum Barry, you'll find the members on here are a friendly and helpful bunch 🙂
usually towbars cannot be fitted either due to the running gear of the vehicle or due to the chassis set up. This can even includebthings like exhausts being in the way etc.
Or Audi may not have approved the towbar for your specific model of Q3.
my advice would be to contact witter or westfalia to see if they fit them.
cheers
Steve