I too have the clunking sound...
I gave to a garage who inspected the axle boot and told they have no grease inside.
he told the clip holding the axle boot was broken
as a fix, the garage first filled the grease, and then put new clips to the axle boot.
[ however the sound was still there

]
this was in january, so i assume any grease that had leaked on the car body should have disappeared by now by car washes...
recently - a week ago, i changed my tires, they offered a free vehicle checkup, where he inspected the bottom of the vehicle, and the mechanic showed me ALL GREASE splattered near the axle boot. so i assume its gone again.
the clunking sound has been there all its life, i dont know if its due to these axle boot problems or the intermediate shaft problem...
however i care for the axle boot, and i will be replacing the axle boots within 2 weeks...
i really dont know if this will fix the clunking sound or not (hope it does)