One problem related to air bag not deploy has been reported for the 2000 Lexus GS400. The most recently reported issues are listed below.
On July 2 ,2009, my wife struck another car broadside with our 2000 Lexus Gs400. The point of impact on the Lexus was with the left front portion (headlight area) of the front. She was traveling approximately 35 mph, and did not have time to brake. The impact, and seatbelt, cause a moderate sized bruise on her left breast area. Lexus indicates their airbags deploy on frontal or "near frontal" collisions at 8 to 14 mph. Yet, in this case, what I think is a "near frontal" collision, the airbag did not deploy. I contacted Lexus, but they contend it was not a "frontal" collision, and therefore the bag did not need to deploy. Then why do they indicate that in "near frontal" collisions the airbag will deploy? I firmly believe that the speed and point of impact should have deployed the airbag, and yet it didn't. I have photos of the Lexus should you wish to see them.