I had front lower ball joints done on my C230 at about 100,000 km's (62K-miles) after driving on our pot-holed sorry excuses for roads. They were slightly worn, but nothing to get too uptight about. The dealer happily replaced them under warranty.
I have talked to other W202 owners in Canada (terrible roads) that have replaced them as early as 60-70K (50-45K-miles).
I wonder about those rear rotors though! That is pretty low mileage. I'm on my third set of fronts, but the rears are original, just a set of pads. And I'm far from easy on my brakes. I do know some dealers that don't install new pads without new discs, and his dealer might take that approach.
However, Mott's comments about stop and go driving might wear them down much faster. I'm pretty easy on them in town, but work 'em like crazy given the chance in the mountains.
Glad to hear the dealer caught the codes early before running problems came up.
My sister-in-law and her husband live in Sydney. They bought a Renault 306 drop-top, and love it. When they told me what they paid, I nearly fell over. "Why didn't you get a Mercedes" I wondered aloud. Then they told me the prices of Mercedes in Oz. YOUCH!
1998 C230 "Black Betty"