This problem started happening at about 65,000 miles and has occurred three times. I haven't had it looked at yet. When the car is stopped at a light, or in stop and go traffic, or parked (but on) for more than a minute or so, it will suddenly jump & shake. Once this jump & shake occurs and you try to accelerate, the car will move forward but the entire car starts to shake, it almost feels like you're driving over gravel. The weird thing is that if you turn the car off and turn it back on, it then drives perfectly. I don't know if this is transmission issue or something else but I've never experienced anything like this.