BMWs before the MINI used to do this also, rare but it did used to happen, sometimes due to corrosion though, In My Opinion that's why they seem to be galvanised (silver) now, the 1st of the MINIs had the black arms top and bottom and then from about 02 reg they changed to the silver colour which don't seem to corrode as much
.
However while working on peoples MINIs before I have noticed that the rear arms have been damaged sometimes quite badly (like a dogs hind leg), and the owners have been none the wiser, whether it be from a previous accident or from being curbed hard (usually combined with damaged / curbed wheels
), I've also seen people, mechanics included jack cars up where they shouldn't, as stated previously
.