platemessages
Not out to just promote your website then !
There used to be message display 'boards' to show in the rear window with limited messages.
It was not successful however.
I do understand the temptation to communicate with other drivers but there is already the 'unwritten' learnt language that motorists have, usually from direct hand gestures and facial expressions, car positions etc.
I am not convinced that this warrants to be in the 'brainstorming' section, as what you have 'exists' than a concept, but let's explore it a little ...
By providing a message (whether correct or not) at a later point it allows some people to 'blow off steam' whether they have 'correctly' understood a situation or not. Now while this does avoid the issue of 'engaging' at the time, which is potentially highly dangerous, what is actually gained by placing a 'message'.
It will mean that drivers / riders would need to correctly note number plates and perhaps other details too. If there is a motoring situation that needs all their attention, then this might encourage distraction, when they are trying to observe un-necessary 'details', at a crucial moment.
Whilst a passenger might observe some details, it might be at the cost of missing something more crucial too.
When any incident happens on the road there is (in the classic phrase) always two sides to the story. There are many studies that show that witnesses are awful at observation. It would be wrong to encourage motorists to think that they might be right, than to question their beliefs.
Also if someone isn't as skilled, knowledgeable, or of the same ability, or as aware as another motorists, then they might make a very wrong conclusion i.e they overtook on a blind bend.
I would be against the promotion of people's private information, which includes their numberplate, car details and the fact that they might be at a certain location (or a clone car was) on a certain day, and some description detail too. Anyone that wants to be vindictive against another, could have a field day, and who is to say that it is not just all baloney !
So the discussion cannot be taken seriously.
Once a discussion is under-way about an incident, why not keep the info private, but just allow the facts to help promote education and a learning platform.
What might one gain from a compliment from an unknown source ?
It is meaningless, as you have no concept if that comes from a top class motorist, or one with the lowest ability. Any good motorist worth their salt will care little for other's opinions anyway, and many excellent motorists actually are often 'but just a shadow' around others, so do not want to be 'noticed' anyway.
So where will this lead you, or those that contribute to your concept - into liable / slander cases, maybe?
So what might be the positive when someone provides a nice comment about another's capabilities - nice but worthless IMHO.
Even if you played a 'points game', where will that take anyone ? It too is meaningless - why because let's say a traveller takes a long night trip, but only passes 100 vehicles and non of those happen to know about your site, nothing is mentioned.
So a good driver may go totally un-noticed yet might have driven perfectly and handled 2 incidents with exceptional skill. So you are only appealing to a certain sector of motorists that interact at busy times, and wish to mention those experiences publicly.
We become good riders and drivers (road users) because it is in our own self interest to do so, not because we benefit from others recognising the fact.
However discussing incidents (the good & the bad one's) at Safe Speed, without all the personalisation, may help some to improve their knowledge and skill, and with experience, might perhaps improve ability and obtain a greater understanding about how they might become a safer motorist.
I can't see a true gain from any of the personal angle that you propose - do you ?