Removing the airbag isn't a great idea; it is explosive, after all. On my A3 GTI, access to the DIN slot is considerably easier if you remove the rest of the front panel controls.

1. Remove the ashtray
2. Pop off the fascia around the climate controls using a flat blade screwdriver
3. Remove six philips screws securing the electronic AC controls, lighter, and frame around the climate controls. Pull that part forward a little and let it hang down in front of the dash.
4. Push the three climate control knobs back a touch and then down into the space vacated by the ashtray and lighter.

This gives you access to the bottom of the DIN slot. From there, it's relatively simple to thread supply wires down to either footwell, and from there to the kick panels and the rear of the car.

I was trying to work out a way to hang the empeg under the knee bolster in the passenger side, because I need to keep AM capability in my headend for road closure information (shout out to Grass Valley and highway 49.) That doesn't look too likely at this point; the enclosure I'm using just doesn't work without unduly cramping the passenger's toe room. So it goes. Guess I'll just have to wait for the AM/FM tuner module, and then grit my teeth and install heavier amplification and subwoofers. Oh, the trial.