The vibration that you are having over 60 miles per hour are probably just tires that are out of balance. Check your tires condition, and if there is a lot of tread left, then take it to your local tire store and have them balance your tires. That would be the best place to start. I recommend the Michelin MXV4 Energy tires, size 205/60HR15, instead of the 195/65HR15's that they come with. As for the car in general, 1993 came with the 104 in-line 6 cylinder engine that tends to leak a lot of oil from the front cover and rear head gasket region. Other than that, it is a great car. Mercedes just has bad rubber and gaskets in their cars, and they are known to leak oil. I think you will enjoy the car very much.
Mercedes-Benz Factory Trained Technician