Driving this morning and all is well. I get an audible beeping tone (3-4 beeps I think it was). I get no warning/caution lights in the dash, gauges are all normal, car is running normal. It only happened once. It was pretty loud. Since it caught me off guard, I couldn't quite tell where it came from. Anyone know what that is? 97 B4 Passat TDI 5 spd (U.S. model).