A4 vibration problem

Hi I wonder if anyone can help with a proble I have with my 2.0 TDi A4 Avant, new in Mar 2006 and with 24500 miles.

I had new tyres fitted to front at 23000 miles - no porblem but overworn n inside - tyre fitter recommended I have alignment checked.

I had been hearing a whining noise form the rear which he informed me was my rear tyres - worn unevenly in patches - once shown I could feel the uneveness of the tyre ( lumpy, is this scalloped ? )

Audi dealer reset "minor" alignment after replacing tyres -All in all £300, the biggest repair bill I ever had on a car barely 13months old.

However, the car vibrates - feel it around 35-40mph but at motorway speeds its there all the time especially on poor surfaces.

Had wheel balancing checked and redone - ok - but still vibrates.

I'm at a loss, audi says they find no problem with car - its a hard ride.

ITS NOT A HARD RIDE - it used to be smooth.

I am feeling that the vibration AND the unveven rear tyre wear it points to a shock absorber problem, can see anything directly - bounce test seems ok - BUT - last night going over a speed bump I could swear the front wheels bent over bump/bump but the rear bump/bump followed by the vibration being worse and gradualy tapering off over a second or 2.... may be my imagination.

what also may be my imagination is if on motoray I drop the car out of gear the vibration doesnt seem as bad... nor does it if I keep to same spped but drop from 6th to 4th gear.


Confused.....please help