Your Parked Car Gets Dinged By an Unknown Driver. Now What?

A British reader named Dominic Ellison sends the following photo and note:

I saw the attached notice in the window of a neighbor’s car that had been pranged and lost its bumper.

I felt that it was an interesting test in game theory and was reminded of what I think is called the Prisoner’s Dilemma, as the reader must certainly ask a number of questions:

Does the owner really have CCTV evidence? If so, why does the poster not allude to make, model or registration?

Would the consequences be genuinely worse if not come forward? For example, was it a drink driver not wishing to be identified at the time?

In case you have a hard time reading this, here’s what it says:

The driver who did this damage to my car has till end of week, to come and see me.

You were filmed on CCTV and recorded.

If I do not hear from you by end of the week I will take the tape to the police. That will cost you more than replacing the bumper.

I know more than you think. Surprising the damage a small car can do. 

0782 635 9091
172 Waller Ro.

It strikes me that it costs the victim nothing to make the threat, so it is quite possible that he/she is lying about the existence of the CCTV footage. Interestingly, however, he/she is perhaps inviting further trouble (from any- and everyone) by listing his/her phone number and address.

On the other hand, depending on the source of the CCTV footage — did the camera belong to a shop? a municipal government? etc.? — it is quite likely an ordeal to get the tape and take it to the police, as threatened. Moreover, it may be hard to get the police to pursue the case if it was only a fender-bender (or, as Dominic might put it, a bumper-pranger).

What would you do if you were the guilty party (and, of course, just happened to revisit the scene of the crime and see the sign — perhaps the most unlikely element of this whole story)?

What evidence do you think the victim really has? Is the “small car” crack simply a bet on the favorite?

And what do you think overall of how the victim has played the game? What might have been some better options?

Dennis Prouse

Stephen - saw you at a Conference in Washington in March, and loved your presentation!

As for the game theory above, the poor fellow who wrote the note is bluffing with a pair of twos. I feel badly for him, but if he actually had any evidence, he would have used it, as opposed to threatening with it. My bet is that it yields him nothing, much like those folks who tape signs to poles at intersections begging for witnesses to come forward to an accident they had there...


One explanation is that the victim thinks employing the criminal law may be harsh; some people make poor moral judgements - the person may have failed to contact the owner despite being remorseful or the like. Also, criminal charges might inconvenience the victim. This gives the perpetrator the opportunity for redemption an allows the problem to be solved without getting the state involved, which may be more desirable for the victim.


Bluff -- If CCTV footage exists it does not show the license plate, or another scenario is that an eye witness vaguely recalled something about a "small car" but nothing else.

Kieran D that we all know the phone number how long before someone rings the owner to discover the outcome?


I have to agree with Prouse -- given the lack of detail in the note, it seems about 95% likely the author is bluffing.

Why not just come forward with the tape right away? Somebody who hits a car and drive away is not the type of person to come forward, or to come to an easy fair deal if they do make themselves known.

However, suppose the victim notes that the other driver is of a demographic that makes them likely to be uninsured. If he shows the tape to the police, they will charge the driver, but he is still responsible for the deductible and likely will never get that money back (at least in my limited experience). However, if he finds the driver, he can make a deal and have them fix the damage and doesn't report the accident so both parties benefit.

So does the question become then, what is the likelihood that the driver who hit your car has insurance?

And does the UK have the problem with uninsured drivers that the US has? (Or at least the southern US -- I have been in 5 accidents in my life, 4 were the other car's fault, and in 3 of those cases, the other driver had no insurance.)



What? Why would the offender come back to read the note?


Why speculate when you can ask the note writer directly, a simple text will do..............

(PS - I have asked)

[WORDPRESS HASHCASH] The poster sent us '0 which is not a hashcash value.


If he's bluffing it's silly but I can see why he might want to take this route if he really does have evidence.

I have a completely opposite sort of story. When motorcycle touring around Ireland I stopped in the gravel parking lot of a racecourse and dropped my bike. The wing mirror creased the door of a car. There was little hope of finding the driver so I fixed a note on his car with an apology and my address in England asking him to send me the bill for repairs. Three weeks later I got a letter with the copy of a receipt for $40 Irish pounds (this was a number of years ago) and a letter which very subtly implied he knew he had no way to make me pay but hoped I would. I sent him 50 British Pounds (about 60 Irish) and apologized again telling him to buy himself a pint with the excess by way of compensation for the trouble I'd put him to.

Two weeks later I got an effusive letter full of praise for the virtues of honesty and integrity the English are known for & etc. - thing is, I'm American, so I reckon I've done my bit for Anglo-Irish relations.



Last month, on Sunday morning, I walked to my parked Car with a handwritten note "Sorry I bumped your Car, please contact me at number xxx-xxx-xxxx . I will claim against my insurance."

Instead of calling the person directly, I contacted my insurance who were able to reach them and get insurance details. I was able to schedule an appointment to get the bodywork done by their insurance.

A couple of days later, a neighbour walking the dog, enquired whether I knew who had bumped into the car. When I said no, but thankfully they had left a number. He told me he had witnessed the incident on a saturday night and followed up with the person to leave a note on the car.


I call bluff, but it could still work, depends on the perpetrator. Perhaps they are someone whose judgement is clouded by a guilty conscience or a little paranoia (or just not bogged down with the weight of excessive intelligence).

Another tactic the note poster could have used, instead of threats, could have been to make the mutually beneficial argument. This could seem more plausible just because it gives the poster a more realistic reason to go this route instead of just using their evidence. They could say, I have this evidence, but I'd rather not go through the hassle of using law enforcement or have to go through insurance,, this benefits you for the same obvious reasons.


If the note-writer indeed has footage that can prove guilt, the only purpose of the note is altruism (veiled by a weak threat). Even if the offending driver read the note, he/she would probably see through it, unless moved by a similar altruism. But the driver is not going to come back. The sole cost or benefit of this action is the danger involved in putting one's phone number and address out on the street like that.


Find the cost of replacing the bumper, and offer half of that as a reward to the driver if he/she comes forward.


Erm.. Do you really want to publish this address/number in full?

Good dilemma though - Currently i'm in a situation at work involving a dispute with the manager, and my work is scrutinised.. The situation is familiar, if I do something wrong should I say (and receive a punishment), or should I hope it goes un-noticed (risking a larger punishment if found).


I think it's interesting that people are commenting on this picture the way they are. I, for one, work in a building with a number of other companies and a relatively small parking lot out front. We have CCTV coverage all around our building. In the event this was in a similar location, it makes perfect sense to me. In a relatively small office building, the pool of people will be relatively small, it's likely that CCTV footage does exist and can be obtained from building management which would likely not only show the car, but also the perpetrator. Given the options of working things out on a personal basis versus bringing litigation against someone that works in the same building as you and whom you may see everyday seems fairly reasonable. Confronting them face to face may be undesired if the person doesn't really know them because they work in a neighboring office. This gives the person the opportunity to confess and work things out without litigation. While even in a small parking lot, it may be possible that the other party may never park close enough to see the sign, the uniqueness of the approach will surely stir conversation in the office that will likely get back to the guilty party. It could be a bit of a stretch from the actual situation, but it also seems entirely possible to me.



I would call them on their bluff.

legal council

I learned a long time ago, do not threaten unless you mean it. I just bought furniture and the person who took the measurements made a huge error. I received two supposed love seats double the size ordered. I called that furniture company, requested in a nice way and then threatened. I meant it and have proceeded to follow through. As to leaving phone number, I assume the victim is optimistic.


I would simply ignore it, will wait and watch what can happen.


Make it a sob story... something about losing your job and not having money to replace the fender and beg the perp to come forward. I think sympathy would work better than threats if anything would work at all. If you are going to lie at least make the person think they will get some gratification out of doing the right thing instead of making them defensive.


I forgot to add... provide a note saying they can make good anonymously via mail and you may even get some do-gooder to make you their cause of the moment since it's unlikely the driver will ever return


He probably saw the individual (or their vehicle) that did it and knows that person routinely comes around. A bluff might be better than getting into he said/she said type of arguement with someone.