A couple of questions for the A3 experts on possible upgrades:- * Can the Symphony2 cassette/6-disc in-dash CD head unit be swapped for a higher spec unit? If so what do people recommend (something with iPod connectivity would be great). * Is it possible to retro-fit the door blinds into the tops of the rear doors? * What are your thoughts on improving the headlight power. Are these 'xenon' bulbs any good?