I just got my LS430 a few weeks ago, and I just FINALLY figured out how to adjust the 18-way seat with the help of this diagram (thanks to Recaro), it was much easier in my first car (circa 1989) that had only two adjustments you could make - seat back tilt and front-back position!

 

I want side bolster adjustments

 

I know what you mean, when I corner hard I sometimes feel myself slide across the seat.

 

I wish the lexus seats dropped lower, so that I have more head room...

 

possibly the drawer under the seat that prevents that..