Have a strange noise, buzzng which increases in tempo as speed increases. Wonder if it's a wheel bearing, inner or outer or am I way off base. Just replaced a broken rear coil spring which I thought might have been the source but no luck. Bad spring out, good one in, and still the noise. No vibration, just the noise. 98 1.4T quattro 95k miles. Oh, also, the noise goes away for a second on right curves, when I unload the right rear wheel for a second. ( The fun part).

 

i had a similar problem but when i accelerated it i didnt hear the noise but when i coasted i heard the noise. turns out the wheel lugs were just a little loose.

 

See if the noise is present if the car is still and you rev the engine. If so, that would suggest that it is the fuel pump. Drop the rear seats and have someone try to crawl around in the trunk while driving to better localize the sound.

Bearing noise is more or a grinding noise. It should also change if you turn the car slightly while driving. it should get louder if you turn the car away from the side the noise is coming from.

If your car is quattro, you may alos want to check the gear oil level in the rear differential.