several months ago started noticing undercarriage noise when going over small bumps (i.e., railroad tracks, speed bumps) at low speed. Mechanic test drove and heard noise, but was unable to locate source. Checked all suspension parts, struts, arms, motor mounts, etc. Does not appear to be anything vital, but is VERY ANNOYING! (Almost sounds like a loose body panel or plastic shield, but we checked that also). Otherwise, this is a great little car. Anyone have a suggestion?