1) There is no way of muting the stereo via the MFSW. I assumed pressing the volume scroller would do this as this is the functionality that is on the new Generation II+ and RNS-E head units. Most other vehicles that have volume controls on the steering wheel also have a mute button.
2) The left hand scroll wheel appears to work in reverse - scrolling down gets you the previous track and scrolling up gets the next one. This is slightly counter-intuitive and is the opposite to the way it is in most other vehicles. One of the reasons for adding the MFSW as an option was so as not to have to remove my hand from the wheel to change tracks. To be honest, I find it more of a distraction having to stop and think which way to scroll the wheel before changing a track while driving.
3) When in Tuner mode the left hand button changes from the currently selected station to the next available station up or down the frequency range rather than scrolling through the presets. Again, this causes more of a distraction as if I want to change from Radio 4 to Radio 2, for example, I cannot simply scroll the wheel to preset 2, I need to scroll the wheel, wait for it to find the next station, check if it is radio 2, then repeat until it finds radio 2. The quicker way to get to Radio 2 is to reach across to the head unit and select it from there - again causing me to remove one hand from the wheel and negate the safety advantages of having the controls on the wheel.
4) The manual states that the MODE button will change between Phone,CD,& Tuner. It doesn't. It just switches between Phone and whatever mode the stereo is in. Again, I need to remove my hand from the wheel and reach over to the head unit if I want to change from Radio to CD or vice-versa. I took my car back to the dealer a week after purchasing it in January of this year to get this "fixed" as it wasn't functioning as per the manual. After a few phone calls from the dealer to Audi UK I was informed that this functionality only applies to cars with telephone preparation and only changed from the currently selected mode to the phone and back again. When I said that's not what is in the manual I was advised that an insert was being produced for the manual to advise of the correct functionality.
This is my second Audi A3, and when I ordered my first one in 2004 I neglected to order the MFSW. The radio\cd mode selection and volume controls with mute function were one feature I missed from my previous non-Audi vehicle - for both convenience and safety reasons - so I made sure when ordering my current A3 to add the S-Line MFSW as an extra.
I'm sure you can appreciate my disappointment to discover that not only does the wheel not function as expected, but that by adding the MFSW as an option I am actually more distracted at the wheel when trying to change the radio station or track on a CD and also have to remove my hand from the wheel to perform even the basic tasks the wheel was supposed to be able to do.