Hi all, Was struggling with this on my own and thought I'd ask the experts. I have a 2007 A3 sportback that to my horror has no rear speakers. I have upgraded the head unit (I think it was the chorus originally) but would like to fit some rear door speakers (plus maybe tweeters and sub in the boot). Looking for your recommendations but I was thinking of buying used OEM equipment that will fit right in. I have the following questions: 1) Will a used OEM rear sub unit fit without modification into a car that shipped with no rear sub in the boot? I.e. are all the mounting points there and it fits behind the standard plastic cover? 2) Does the rear sub amp power the rear door speakers as well? How can I work out the wiring connections on the sub unit? 3) Do the rear door handle tweeters connect to a powered or unpowered system? How? 4) If I buy only the used rear OEM door speakers do I have to have the amp as well? Or can I just connect them up passively to the head unit if I don't buy the rear subwoofer unit? ... or should I just buy some new cheap off-the-shelf passive speakers for the rear doors with integrated tweeter and glue them in place? Many of you must have fitted rear speakers to a factory front-only car, so what's the best route to take? Thanks in advance for any help!