Ride really hard when going over bumps etc, also back end of car sliding slightly when cornering (even at moderate speeds) on drivers side.

Is this just the shocks that need replacing or could it be a problem with the rear driveshafts?

 

could be the rear shocks failied

 

Have you checked your tyres recently?

 

Yes, plenty of tread on rears - just passed MOT

Taking it to AS Performance tommorow to get checked out.

 

might be worth checking your rear drop links one of mine snapped and back end wanted to slide all the time