Werd Noise on S4

[natie954]

Hi Guy's . This is my first querie on this forum , although i visit it regularly.
I've got a 2005 B6 S4 ( 4.2 V8 ) . It has 57 000km on the odo . Had it serviced 4 month's ago . It's still under Maintenance Plan and Waranty .
About a week ago my wife said that she's hearing a high-pitched wighning noise from the front left side of the car while driving in trafic at aprox 30km/h . I went for a drive and heard it too . Didn't sound like a wheelbearing and it didn'y realy worry me . Last weekend i washed the car and took it for a spin and heard the noise much clearer . I went away for a few days for work and when i got back she said it was getting harder .
I had the Road-side asistance come out and have a listen but the mechanic said he has never heard a sound like that and dont know what it is . I'm taking it in on Monday to the nearest dealership for them to have a look . Can it be the Tiptronic gearbox ?? Wheealbearing ?? Dry seal ??
It worry's me a bit , cause i think it comes from the gearbox . I'm in South Africa and the technicians over here sometimes worry's me , sorry for being honest .
Anyone else ever had a noise like that ???
Any help would be appreciated .
Regards
natie954