Individual radio speakers cut out at times and require volume to be turned above 15 or 16 to restore.
Home-Link garage door opening system works only every 4th or 5th time.
Climate control fan occasionally jumps from minimum to maximum when pressing the fan-down button to turn off.
Controls on driver side (windows, locks, etc.) do not light up.
For 3 days, speedometer floated up and down by 10 kilometers per hour while driving, and would not move outside the range of 10 to 70 kilometers per hour, regardless of vehicle speed.
Remote key-less entry turns off alarm, but does not unlock the door. The key must be used after using the fob.
The power door locks do not function on the driver door.
All power window controls do not function, preventing the opening of windows in the vehicle. This has clear safety implications.
Door buzzer sounds constantly while driving the car.
Interior light does not turn off while car is running, even while driving. This is very unsafe at night.
Passenger seat squeaks constantly from normal vibration of the vehicle while driving at speeds above 90 kilometers per hour.
Two ignition coils have failed in the vehicle at different times, both requiring replacement. This issue was also the subject of a recall by Audi.
Rear passenger-side seat, once folded down, would not refasten in the upright position, causing the seat to fall forward if the vehicle stopped quickly.
This car has significant, recurring electrical issues that pose obvious safety risks to the driver and passengers.
The car has required over a dozen service visits over the past year to address these issues, and the issues persist.
I advise doing serious research before buying an A4 to make sure that these issues are resolved.