One problem related to tail light switch has been reported for the 2013 Audi A3. The most recently reported issues are listed below. Please also check out the statistics and reliability analysis of the 2013 Audi A3 based on all problems reported for the 2013 A3.
Intermittent problems with exterior lighting. I already replaced one of the rear license plate lights (not a bulb issue) and am now experiencing rear passenger side tail light issues where the tail light and directional signal cease working during the driving process and then start working at random. This appears to be a similar electrical issue like the license plate light. The tail light & directional signal failure are dangerous as the failures occur without warning while the car is being driven.