[s-cars] got a new sound

[Bill M]

Mike, et. al.,
Another thought is that this vibration "could" be worn rubber bushings  
in the rear subframe crossmember that the front of the rear  
differential mounts to.
I had a sort of vibration too about 55 / 60 mph.
Fix was an overpriced but almost new crossmember from shokan.   You  
could probably get new bushings and press them in but sorry I cant  
help with part numbers here.
I "think" someone may have posted them long, long ago, in a galaxy  
far, far away.  Hey these beasts are old!
Good luck!  These things are hard to trace.  Think it through for the  
most probable fix before investing time and dough.
Bill~mit dahkine vibration news~m