Bit of an update...
After completing a report, the Met have sent a letter to both myself and the car driver. My letter states the matter is being looked into (also got a phone message from them asking me to supply a copy of the DVD of the collision).
I don't know what the drivers' letter said but he texted me to say he got the letter:
'claiming I drove without due car [sic] and attention... I'm afraid that's that [sic] information is incorrect, as it was you that was not visible to the public eye [sic]... I will appeal this claim and if found guilty I will make a counterclaim against you regarding this matter, on the grounds of poor visibility on your behalf.'
I reported it mainly to ensure I was covered financially should he decide to play funny buggers but it turns out the damage was able to be fixed with my routine service that was kind of due anyway. Also, I wanted to ensure the incident was recorded statistically, I was going to request the police do nothing more than write to him and inform him he must be more cautious in future but given that he clearly doesn't think he did anything wrong, plus the thinly veiled threat, I'm very inclined to push this as far as the police are prepared to go.
He doesn't know I have the incident on camera yet but he might be surprised to see my 2 sets of lights visibly flashing in the puddles of rain on the ground as we swapped phone numbers...