First, I'm a bit surprised that your local police force has the manpower and time to waste chasing up a complaint from a member of the public that a motability car's paperwork may not be in order, bearing in mind that most forces can't be bothered to follow up reported burglaries, if stories in the popular press are to be believed. But if that's what the police officer has told you, that's what he's told you.
If you want to follow up his suggestion to make a complaint, check your local force's website for how to do so. Or (bearing in mind the history of problems that you've had before) write straight to the Chief Constable (website again).
Simply say you want to make a complaint about the number of times your daughter (or whoever) has been stopped by the police for no apparent reason. Give a list of when and where this has happened and what the outcome was (presumably that the police took no further action). I would also add that in the latest incident the police officer actually suggested making a complaint about the number of stops. Not only do you (or your daughter or son or whoever it is) find this police action to be extremely distressing, but you also consider it a waste of scarce police resources.
Ask for an explanation as to why this keeps happening and ask for an assurance that the police will stop doing it.
You may also want to add (see what others advise about this) that the police officer in the latest incident also told you that they had received a call from someone saying that the car's paper work "might not be in order". Say that you are concerned that whoever made this false allegation is wasting police time. (You may want to think carefully about this as it may not improve your daughter's relationship with her neighbour! If the allegation came from the neighbour.)
Those are my initial thoughts but it's a bit late to be thinking clearly. See what others suggest rather than just relying on my suggestions.
[The letter really needs to come from your daughter (or whichever family member keeps being stopped) and not you, unless you can make it perfectly clear in the letter who it is that is being stopped etc. and that you are complaining on their behalf. Is that clear?]
And dx what success have you personally had when dealing with cases for people in the county court.... when pointing out the above
I have asked you several times for your direct court room experience. Yet it hasnt been forthcoming
Please prove your statement that vcs lose most defended cases ?
Again what you state doesnt stand up for the reality of the court circuit
Don't touch them owe me £500 since January 2019 make excuse after excuse. Seem they always have software problems sending money out. Keep saying they will call back or email nothing been chasing it now for 6 mths the phone staff always have the same banter we will chase it up and get back to you then nothing!