I bought this car new back in 1990 and it has lasted me 15 years so far. I love it and it is very fun to drive. I have also taken it to Massachusetts when it was new about 4 times. Coincidentally, I have had problems in the past with a cracked antifreeze tank and radiator. Otherwise, it is an excellent car, but living in Connecticut with harsh winters, I can't drive it as often as I would like. My sister has the new 2005 S430 and I still like mine better because the build quality is better and it is actually bigger (I did the dimensions)!
Sunroof, antitheft system, power passenger seats, heated seats and mirrors.
Like Adeluca said, bigger engine. Better fuel economy, and bigger gas tank.