This happened to me and yes I did get the number and report it.
Surprise surprise, they couldn't trace that vehicle as it was still registered to the previous owner. So they couldn't do anything, yeah sorry about that...
So through that little loophole, the scumbag who almost knocked me down basically gets to be above the law, because he knows full well that anyone taking his number and a description has f-all chance of seeing him busted
. So let's face it, he's almost certainly driving without tax or insurance, oh and possibly doesn't even have a licence, and no wonder he's happy to drive through pedestrian crossings - no comeback, you see?
Before anyone points out that this isn't exactly the fault of the police - I know, the whole incident leaves a bit of a nasty taste in the mouth though as when I reported it, the person on the other end of the phone (policewoman? not sure) got the details of the incident, then:
'Yeahthanksforreportingbyeee'
Me: 'Hang on hang on don't you need MY details?'
Her: 'What for?'
Me: 'Well if you trace this guy to let me know that you have done, and to see if I want to take it further and how! - you don't even have my telephone number?!'
Her: 'Oh yes that's fine we can do that' 
I give details. Surprise surprise, am contacted the next day with the above, and the news that they've 'closed' the incident. Super smashing lovely great :)