Auto or manual? (Some clutch bearing conditions can cause this in a manual.)
What is the level of fluid in the transmission? When was the fluid last changed?*
What is the level of fluid in the differential? When was the fluid last changed?*
Are the motor/transmission mounts intact?
Are the exhaust hangers all in good shape?








*The car is sixteen to nineteen years old, if you are running the original fluids, go find a mirror. Stand in front of it, and slap yourself really hard until you lose consciousness. If you'd rather not do this, your wife/girlfriend may be helpful here.