Octavia VRS rear end issues

Hi guys

I am having a strange issue with what feels like the rear end of my mk3 vrs (multilink)

When driving along, the car "tram lines" and feels loose at the rear. When I put the foot down to overtake someone, the car torque steers violently as I change lanes.

Its on new Bilstein B8 dampers, new eibach springs and all the bushes have been replaced and 4 wheel alignment has been done. Results below.

It also has new ball joints, drop links and track rod ends up front.

Anyone any ideas? im almost thinking one of the rear bilstein dampers is faulty from the factory

Thanks