‘03 was the First year of the supercharger. Used the Command Nav unit that uses a CDs in the head unit for the map (7 of them for USA). Also plays up to 6 CDs from a cassette you load in the trunk. Has TV button in Europe. Can be upgraded to BT with a “puck” that sits under arm rest.

’04 used the updated Command unit using DVD for maps. Better screen and routing algorithm. ‘04 has more new car smell remaining in it.

If if you get a better deal on ‘03, go for it. There might some day be a premium for the 1st year car when it becomes a collectible....in 2035.

Buy the car with repair history showing the ABC system was recently sorted or repaired. Or otherwise low-ball somebody whose car is resting on its bumpstops and fix it yourself for cheap. (Parts cost money). Another common problem for both years is the air vacuum lines that operate all the door locks/soft close functions.

Search nOOb. Couldn't resist.

Rule #1. Don't buy the first year of a complicated new model such as an S-55 as MB quickly realizes a number of things need updating. Much of which done for 2004.
Rule #2. If you can swing it get a 2008 and newer 221 S-Class as soooo much of what was so troublesome in the 220 chassis has been solved.
I wish the supercharged 5.5 liter got used in the 221 Chassis or MB turbocharged the 6.2 right out of the gate. Alas... They figure it out over time.

Regarding Rule 1: I usually agree. However, the SL55 AMG was launched a year earlier and those are the guys that suffered the supercharger pains first. I still learn a lot from their forums. The supercharger problems are:
- squeak noise when clutch engages at throttle up
- front bearing wears out and needs replacement.
- clutch surface wears out and needs replacement (rare)

Same problem for all years. I’ve only experienced the squeak (since new, and still there) These are serviceable items on the supercharger, compared to a turbo failure which usually requires complete replacement and fishing out impeller blades from the exhaust.

And if if you want a supercharger (not a turbo), you have to stay in the W220 S55.

Supercharger pain being the squeak it makes for a millisecond as you are about to make the Prius disappear? That; my friend is a first world problem!

They all need to be maintained. I prefer the supercharger. Loved how my E-55 went. Wish that MB had cooked up a clever way to use one (or more!) to make the bent-12 especially amusing. Alas they did not. In any case.... Turbocharger failures are rare compared with the '80s. We all change our oil and use Mobil-1 or another suitable synthetic. Change the oil in your supercharger. You will not forget the odor.

My point being that cars the engines found their way into got a LOT better in newer cars. Many things MB got right in the 221 that were forever annoying in the 220 + new exciting annoyances in the 221.