Hey Mike,

It's just a general roughness in the motor. It's not a driveline shimmy or a tire issue, I know that much. It's as if the motor is just transmitting enough vibration to feel it through the floorboard at times. I just drove it tonight and it was smooth, but last night it was rough. Seems like it isn't a gas quality issue, but I'm at a loss. I'm just used to the car being really smooth all the time.

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

current: 08 C300 Luxury , 92 500SL