Has any 550 owners felt a low vibration/shake when accelerating? I don't hear it really. I feel like in my feet and steering when I accelerate on highway and it is mild, more so when I accelerate gently at normal speeds. In some cars I've noticed this when trying to find gears, but it seems more pronounced in my premium plus. It is not the tires because the vibration is gone when not accelerating and the car is just rolling along. Not sure if it is anything to be concerned about but just curious if anyone else noticed similar issues. Maybe try and pay attention to that and let us know if it is just a body on frame thing?