SRR16

It took me a while to realise that the Cruise Control cancels itself as soon as the double-speed wiper engages. If you have the wiper on Auto then this can happen suddenly during very heavy rain. If you manually switch from Auto to normal single-speed wiper operation, then you can continue to use the cruise control as normal. I guess that Lexus thought of this as an easy way to discourage use of the radar cruise control in bad conditions.

Thanks Martin, I have been bothered by this same rattle for the last few months but was unable to get to the bottom of it. Similar to you, it mysteriously appeared when the car was about two years old. I thought it might be the front passenger seat, but couldn't pin it down. Your fix has worked a treat on my car, so thanks for the detective work. Now I only have the rattle from the drivers-side rear luggage area left to figure out...