If it's a 98, it's a V6. Inline 6 ended after 97 MY. My grandmother had a 98, was a nice car, however hers did have the early 722.6 trans which went south and was replaced at 30k. Might want to check into trans records. Does it shift hard when warm, 2-3? Slip any in 1st? If it looks ok, at least be ready to change trans fluid and filter at 60k - lifetime fluid is not lifetime fluid. Also, the 60k service is about due, which could be north of $500. At that mileage, you may also be looking at new pads AND rotors (city driving?) My '97 C230 was the cream of the Starmark crop when I bought it, 60k service, new rotors and pads, and since March I've still managed to rack up around $3000 in warranty items.

Beware.