I noticed today that MSA has begin to offer refurbished differential hanger brackets on an exchange basis. In their write-up on these new parts, they discuss applications in relation to solving the differential 'clunk' problem and emphasize that Series 1 owners will need to install the Series 2 differential hanger parts and moustache bar in order to be able to use the Series 2 front insulator (I believe that this is because the arrestor strap won't fit otherwise). This made me curious, so I started to look around some of the commonly-used parts vendors' websites to see if anyone was offering the Nissan Series 1 part (PN 55415-E4102, for reference). A quick look turned up 'not available' at Rock Auto and Chesapeake Nissan. Z-Car Source of Arizona offers only used units, and only on special order. Courtesy Nissan lists the part and a price, but that doesn't mean they have it or can get it (I haven't asked them yet). MSA lists it, but warns that it "...has been discontinued by Nissan or another manufacturer, and we are currently in the process of locating an alternate supplier or having the item reproduced" So: Is a new OE Series 1 diff mount/insulator definitely NLA ? If so, are there any known aftermarket options?