I had a vibration at 80-85mph for the past few weeks, and I know vibrations are common for early LS400s. Mine was resoved through Discount Tire's hardcore balancing machine - vibration gone for $40. Worth every penny.

Just thought I'd let those know who also have a vibration.

 

Yup, a simple wheel balance usually gets rid of a vibration. Tires Plus did mine for $20 and my vibration was gone .