I just got a 2005.5 S4 and there is a random beeping sound that seems to be coming from the back of the car. I've read in this forum that it's probably the alarm, but the problem with that theory is that it goes off while I'm driving as well as when the car is parked. Any ideas?

 

parking sensor buzzer if fitted

 

After a little more investigation, and crawling around the car like a fool trying to figure out where the sound was coming from, I did figure out that it's coming from the NAV system / stereo. I know this because when turned off, the screen is blacker when the unit is still powered (beeping occurs), and then it turns kind of greenish when not powered (beeping does not occur). Now I just need to figure out why the NAV system beeps randomly.

Thanks for the idea, but I don't have the parking sensor.