What kind of noises?? There are always some cam/lifter noises if you stick your head near the engine. Belts may make noise if they're old. Interior squeeks and rattles come with higher mileage.
I drove two LS400's - both were pretty quiet, but you don't get that feeling of the road when you drive. I guess sort of like a Lincoln, but not as floaty. Well.. more like a big Camry, but we won't get into that.
2003 S500 Black/Charcoal
1990 560SEL 61k Arctic White/Grey
1988 420SEL Black/Palomino Sold @ 85k
1987 420SEL Midnight Blue/Grey
1986 420SEL Diamond Blue/Grey
1983 380SEL Champagne/Palomino