Motorway judder 1.8T sport avant

Hi all, at anything over 60mph i get a constant judder like a wheel imbalance but just had new tyres :(
I know the rear axle bushes are badly worn and i have them in the shed, just plucking up the motivation to get and do it.
Any other things I should be looking for? besides it feels like its from the front...............
I may be being picky as it is the Sport and has a very hard ride which is not great on Devon lanes!

was it the same before the new tyres were fitted ?
i would be looking at balancing or a buckled wheel first.