2009 Chevy Aveo 5 LT

Recently purchased a 2009 chevy aveo hatchback and 3 months ago my steering wheel started to vibrated. This happens when Im at a red light, If I put the car on park it goes away. I took it to the dealer and the mechanic said that the left engine mount had a crack. So I had that replace, but the vibration is still there. They tryied to tell me that the vibration is a characteristic of the car, but thats just to hard to belive since its fairly new. Anyone has the same problem?