use a head cam.
report it on ctc website on the "stop SMIDSY - report bad driving", and tick the box that says happy for them to contact police
go to local police station and make an "accusation of dangerous driving"
practice memorising number plates, (i can now do it in one glance) and vehicle types and colours
Print out several copies of the relevant sections of the highway code on rule 163 and other sections on VRU's and general overtaking, then hand them to the driver in question.
learn karate and practice your 1" punch on the driver's nose.
accidentally un-clip your shoe resulting in a scratch on the car - if they had left sufficient space as required by the highway code that could not have happened, so either they conciously drove too close (dangerous) or they accidentally drove too close (driving without due consideration), sometimes cyclists swerve to avoid pot holes (rule 163), so you are entiteld to the entire lane, command position.
even if you were blockign him deliberately, he is not entitled to use his car as a weapon and drive you off the road - if you had a 'trained witness' he'd struggle to defend a dangerous driving charge.
if we span his wheels as he left you, he was not in proper control of his vehicle, and I'll bet there are several other things he failed to do. again if the police wanted to get him they could charge him with not being in control. if he was deliberatly not in control near a VRU and he knew you were there (and he did cos you had a conversation with him) then that is dangerous driving.
But having said all this, you won't win, you are a cyclist, and the driver has a big heavy car. he/she has long forgotten the HWY code afterall when was the last time most people on here read it? unless you are very diligent in your evidence gathering kit and practices, the police won't bother coz they'd never get a conviction. even if he killed you it would be considered an unfortunate accident, even though, almost by default you as a VRU have an implied right of way.
also on the horn front, unless it clearly sits within the rules, beware that it can be constued that you caused alarm and so caused an incident that subsequently took place. I was warned of this by a friendly copper and the same applies to bright head mounted lights, they can claim they were dazzled so didn't see you.... hmmm
i really think someone should produce a cyclists evidence camera kit (front and rear looking) with enough resolution for number plates and time date stamping, and tamper proof recording to make it evidence submissable, mind you we'd need to carry "beware CCTV" signs so they are warned, soemthing to do with submissable evidence or sommat in the CCTV regs.
so actually (as my girlf is trying to teach me) stay calm, realise you can't win, and just smile everytime you see a traffic jam.
oh and don't jump red lights, coz it destroys all hope cyclists have of any public support.
tum te tum...