In the pre 2010 Rear axles, there are two different generations of Haldex Coupling. I have a Gen 3 in my 2008 model, and a Gen 4 in my 2009 model. The 2013 on axle is different. The gen 3 needs a a software update if changed for a gen 4. The later 2013 coupling has non-compatible software according to my local specialist. I saw a new late diff assy for £350 on ebay. I was a bit miffed that there was so much planned obsolescence. THe original diffs had too much bearing preload. The pinion bearing was also too small for the job. You want Timken bearings for the best life.