I'd guess it maybe your motor mounts, since you've already replaced the transmission mounts, and it sounds like it's coming from the front of the car.

 

S4 motor mounts (and many other Audi models) are fluid filled and if they pop, you should find the fluid oozing out of the mount. Fairly easy to see with an under car inspection, unless the front mounts have been empty for a long time

If you do replace front engine mounts, consider 034 Motorsport Street or Track Density solid rubber mounts. The street density does not add any noticeable drivetrain vibration and it is a stronger mount than stock.

 

sway bar links!!! get them changed..they are really cheap

 

its either ur control arms,sway bar links or even a blown chock!!!