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...
This driver indicated left at a roundabout going right, then indicated right as they exited the roundabout. He then continued to drive for the next mile or so narrowly missing parked cars and swerving all over the road. When I drew alongside him at the next roundabout why was I not shocked to see him paying no attention to the road and looking down at his phone in his hand. Put your phone down before you kill yourself or somebody else
This driver tugged me off