Check if backlighting of your seat memory buttons '1', '2', '3', '4' and 'Memory' is still working. There is a incandescent bulb and an optical conductor that is responsible for those buttons. The on/off red button backlighting is done with LEDs.
Bulb can be easily desoldered and changed to new. I have changed both sides. One was off. Changed other too to avoid doing it again soon.
Thread here:
http://m.audiworld.com/showthread.php?p=15572602
Original bulb that fits without any modifications:
Bulb can be purchased here:
http://www.ebay.co.uk/itm/1407318945...84.m1439.l2649