I had a Vauxhall piss pass me this morning, triggering the 30mph warning sign, then tailgating a Honda which had dared to get in it's way. My attention was drawn to a car waiting at a junction then a few seconds later I hear a screech of tyres and a bang. The Vauxhall has crashed into the back of the Honda at a roundabout, I did not actually see the crash but may have caught in on camera, cannot check until later. Is it worth calling the Police non-emergency number to inform them I might be a witness. No-one was hurt but the Vauxhall's front bumper was no longer attached to the car with lots of other minor damage. I did not stop at scene as I did not see the actual crash and both people were out of their cars, the Vauxhall driver apologising profusely despite tailgating the Honda moments before the crash.