I only bought my car(03 cp) some 2000 miles ago, everything was fine, no noises anywhere....I took a trip of some 200 miles and the later part of it I was hearing a noise I have previously come to recognise as NO FLUID in rear differential.... this noise sounds sort of like a mild clump, clump rising and falling with rpm....I checked it today and found it was 14 oz low.(a note here my differential is absolutely dry and clean, so no leakage. My owners manual does not tell you what the capacity is but it is not much...I can add that the fluid was probably the original from factory and probably worn out so that when it got hot and thinned out, what there was of it caused excessive play between the ring and pinion gears....the noise is now gone. so if you have something other than the clicking from the dry axle shafts...check your differential fluid.