do it, take it in. just had mine in at northampton audi today, 1400 miles of something small rolling about inside the dash, fortunately not a dash out job in the end but they couldn't tell me what was causing it but it doesn't do it anymore. armrests can have a tendancy to squeak - bad design in the a3 as you can't reposition mine with the handbrake on
also, they wash and valet the car so it's spanking and smells comfort fresh inside
and
I blagged a 3L Quattro A5 as a courtesy, although after the initial excitement i didn't like it that much, couldn't get a good driving position, couldn't see the end of the bonnet, couldn't see properly out of the back but mega torque made up for it!
sorry dude, major rambling, to recap, take it to the dealer