I bought mine last summer with 12k, CPO plus some factory warranty left. It feels like a reincarnated and updated 202, which was the best MB I've owned. It has some typical modern MB issues, lately it has begun choking out after I start it, but this will soon be address under warranty (24k). I suspect at 68k, yours had encountered and received warranty repairs, although once most MBs hit around 5 years/70k, expect to replace some rubber bushings in the front end in the near future. I'd make sure the trans fluid has been done at least once (39k), and that hopefully, oil has been changed at least every 10k, but preferably every 7500. If 10k, make sure the records say Mobil 1, and if not, check for sludge.

Overall, mine's been very trouble-free and appliance-like (sort of boring, but hey, it's a C-class). Good looking car, quiet, no rattles, I think with proper maintenance these will be long-lived cars. I have read accounts on other boards of 150k+ miles without major issues on the w204s.

PS - when checking the records, see if the cam magnets have been replaced (the c300s, especially early ones, have an issue with these, and I expect mine to need replacement at some point).

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former: 83 300D, 97 C230, 93 400E

current: 08 C300 Luxury , 92 500SL