I have '99 LS and it has 152k on it.
Since I bought it few months back, the steering wheel gives lot of vibration regardless of road condition which differ in intensity with speed.

I have put on new Michelin tires and got it balanced and subsequently got it Aligned at firestone Inc.
But to no avail. It still has the same problem.

Any Input about what might be wrong. It does not bother me but if it is just something which can be fixed with little effort I would definitely opt for it.
I am not DIY person.