At its birth in 1989, the LS400 was designed for one purpose: To be better in every way than than a W126 Mercedes S Class, a E32 BMW 7 series and a Jaguar XJ.
In their quest to achieve this Lexus engineered a car which was quieter than a Rolls Royce, had better mechanical reliability and durability than the Germans, more smooth than a Jaguar and attention to detail. Without doing this they would have had no chance in breaking into the luxury car market and the LS400 would have gone down in history as another Honda Legend / Toyota Cressida / Mitsubishi Sigma / etc etc