The only other possibility that wasn't mentioned is subframe bushings or the bushings on the sway bar itself. But again, they would be when the car is driving over roads that would make the worn parts bump. I don't think it would make a noise on a smooth, bump-free road and wouldn't sound rhythmic unless you're driving over expansion joints in the road. 
__________________
Chad
[Oo{=|=}oO]
1985 300TD - "Red Dragon"
369,XXX miles - (540) Borolo Red - (154) Java MB-Tex
Chassis 1231931F050455 / Engine 617952 12 106600 / Trans 722315 02 638091
1985 300CD - "Gladys"
208,XXX miles - (702) Smoke Silver Metallic - (154) Java MB-Tex
Chassis 1231531A226271 / Engine 617952 12 094266 / Trans 722416 02 162489
OBK#44
"Pleasure in the job puts perfection in the work." - Aristotle (384-322 B.C.) |