Had the bushing set installed yesterday. Very troublesome for my mechanic, the bushing removal (even with the Z1 tool) and the replacing of the differential. Nearly seven hours, all told.

Like my review of the subframe collars, I find the diff bushings make little change to car behavior during street driving. NVH increase is negligible. However, I had coil-overs installed at the same time so I can't determine which of the two has caused the slight increase.

So far, the Vibra-Technics urethane trans mount has made the largest contribution to NVH increase.

As has been mentioned in the the sedan chat thread, do not go to the trouble of the diff bushings until it has ruptured or you have the diff out for some reason. They're a royal PITA to install. Mine were still good but I wanted the Z1 diff cover so I killed two birds with one stone. Thank the Flying Spaghetti Monster I'll never have to do it again.