i have a 2003 SL500. slight vibration at 40 and then again more pronounced at 60 in the Rear. the interior feels like a helicopter air pressure or like a effect .. car runs well at over a 100 mph. not sure if its tires or drive train etc. motor and tranny mounts have been replace/fixed. and rear main seal, upper and lower ball joint and two torque struts, replaced. Tire pressure is good 26 and 29 per specs/door. same size tires.
would appreciate any opinions
thanks steve