I saw the red triangle warning come up on the dash when getting too close behind another car on the test drive of an HSE. I've not seen it on my car though (an S, and not that I've been tailgating ;-)), but I think you get it only with adaptive cruise control, which mine doesn't have. I think you can adjust the sensitivity for when the red triangle flashes up though - I thought it was far too sensitive on the demo car we had the test drive in.