Being a relatively new owner of a Lexus GS MkI, I have read a lot about the various "wobble syndrome" of the steering on the GS. Mine has "something" as well, and my local dealer sorted out the tracking and said that is the only thing to adjust and it is now perfect (they probably didn't even drive it...).

Well, after adjusting tracking the steering has improved but is still far from what can be expected from a luxury car like the GS. So I went searching the web and found this useful article.

I can now relatively confidently say that my car has caster problems ("If the caster is equal but too negative, the steering will be light and the vehicle will wander and be difficult to keep in a straight line"), and I hope that my appointment with Lexus on Wednesday for a full 4 wheel alignment will sort out that and whatever else there is with the steering.

And finally, if your tyres are worn unevenly, you need to get new tyres on before doing a 4 wheel alignment - I'm getting my new Pirelli P7 on just before the alignment

Happy reading.