Out of the blue,my 91 NSX developed a rumbling,mechanical-sounding clunking-type noise,just yesterday.It seemed to be coming from the passenger side rear and is only noticable at very low speeds,around 2-15 mph and at cold start it isn`t there;once I`ve warmed the car up it begins.At speed there is nothing.At first I thought it was some loose items in the trunk,but it isn`t.Wierder yet is that on my drive home this evening,it didn't occur!Got a feeling it`ll be there again tomorrow though.It wasn`t a LOUD noise but certainly wasn`t right.Anyone have any ideas as to what the possible problem might be?Car was very recently serviced at 62K at Accura dealer and has been running like a dream....Thanks to all in advance and I`ll let you know what transpires.