Today while driving, I started to hear a noise almost consistant with
the rotation of the tire.  It did not happen all the time & started
after about an hour of driving.  The clunking noise was similar to the
tailpipe banging against the bumper (but not so tinny).  It would appear
and disappear when I let off the accilerator or stopped by the side of
the road.  Seemed to be worse going downhill or around a corner.  Any
suggestions would be appreciated; motor mount, cv joint, transmission?
Thanks!