Film them. Then send the company the link to the video. Trust me, if this is true then they certainly would not like the image their employees (or managing directors even), portray. And you have every right to do this.
Nearly clipped me when overtaking me at an insanely high speed in the rain. Also, the license plate was on a black Ford Kuga, not a grey Citroen C3 like the MOT states...
They were sitting at a green traffic light, more interested in the accident to their left, I tapped my horn to make them aware of the green light and I get the bird for doing so, maybe pay more attention to the road in future.
This driver tugged me off