During driving an issue arose where the acceleration had to be performed in order to avoid a potential accident. The gas pedal vas depressed but the transmission would not downshift or accelerate. After about a second or more the transmission finally downshifted and the vehicle accelerated. I was able to steer out of trouble and fought the in order to do it. This is a know issue and programmed by Lexus. Who in their right mind does not allow the car to accelerate when the gas pedal is depressed. this issue ue seems to be with IS500 only. the mechanic did acknowledge a slow shift and this is by design. I am afraid to pull into traffic since the car will not go. It will start to go then slow down or back off and then after it downshifts it picks up speed. The time is so slow that I could get hit if the approaching traffic gets to me despite knowing that the distance is sufficient to safely pull into traffic. the car is unpredictable. In my other cars I have no issues like this. I have another Lexus vehicle and it does not do this. Many have reported the slow downshift and Lexus mechanic say it is by design. A downshift of one second or more at 60 miles an hour is 88 feet of travel. The car is not safe to drive because the driver is not in control. If you have to accelerate to avoid an accident or get out of the way you will not be able until the stupid car decides to. I have driven other Lexus models and they do not do this. Only IS500 does this. It is so unnatural that you press the gas pedal half way down and nothing. The car has to accelerate when you need to accelerate. Lexus also sells performance but it is not a performance car. Somebody is going to die due to this issue. I am nervous driving the car and I feel like I am out of control. This is a continuous problem. So far I almost got into 3 accidents due to this issue that could have resulted in a serious accidents.

- Warner Robins , GA, USA