I rebuilt the rear suspension, transmission, brakes etc of my car a few months ago – including an MSD poly diff mount and yellow poly beam mounts. I've no complaints about the handling (lots of great traffic-free roads here in southwest France!); but the whines, clonks, road noise, etc give the impression that everything's pretty knackered, and destroy my enjoyment of driving the car to an extent. So I'm going back to standard mounts . . .