But the Honda, which was recovered last week and is now sitting in a lock-up at St Ives police station, near Cambridge, provides the first real trace of the couple who disappeared from their home in nearby Ramsey the day before they were to hand back to Cambridgeshire social services the children they adored, and had fostered for six months with a view to adoption.
Inside St Ives police station, in an investigation room plastered with already-fading newspaper cuttings about the Bramleys' flight, two large plastic bags of clothes and belongings, left in the car boot, present more puzzles.
There is Hannah's pink anorak with fluffy, white-fake-fur-trimmed hood, and a similar winter jacket, in maroon, belonging to Jade. Jeff, 34, and Jenny, 35, also left jackets behind. So slight and small is Jenny that hers was bought in the teenage section of a department store.
Why did they leave behind the clothes - along with children's car seats, an empty handbag and a stack of plastic-wrapped tea bags - when these did not figure in any description issued by the police? Officers were unable to establish what clothes the family had with them.
The car is the police's biggest - in fact, only - breakthrough. Remarkably, it sat in the same York street for five weeks before residents reported it to police, despite all the "tug-of-love" publicity and a description of the car - still bearing its publicised registration number - having been issued by police.
The Honda's discovery, and a "good" subsequent sighting of the family by a retired clergyman on the North Yorkshire Moors Railway last weekend, means hope for a police team hitherto bereft of leads. Seven St Ives officers have scurried north, but excitement is mixed with trepidation. There have already been sightings, from Ireland to Lanzarote. This one, like the others, could amount to nothing. For the Bramleys, a quiet, law-abiding couple described by relatives as "Mr and Mrs Average", have proved to be formidable fugitives, as elusive to the police as quicksilver. "I expected we would find them in a matter of days," admits Mr Nicholson ruefully. "In this day and age, in this country, it is amazing they have managed for so long."
Just how the Bramleys are managing is the major puzzle. Though the couple are described as frugal, the pounds 5,000 in cash they took with them must now be close to running out. However, they have yet to draw on further funds.
The police have suggested before that the Bramleys have not been caught because they are "so ordinary", easily camouflaged among the hordes of other thirtysomethings trailing round with small children. But the police are considering two other possibilities: that someone is actively helping them, and that a public, blinded by sympathy for a childless couple who must return the little girls they thought of as their own, is proving to be less vigilant than usual.
Social services deny ever saying that the Bramleys were "too strict", and totally dismiss rumours that they were considered too religious. There is also absolutely no suggestion of any kind of abuse. Quite simply, a spokesman says, it was concluded "after working with the couple for six months" that they lacked the special parenting skills Jade and Hannah needed. The decision, the spokesman insists, was not taken lightly. The authority claims that this is the first time in 10 years that it has terminated such a placement.
That the children had already suffered far too much in their short lives is indisputable. It is just over a year since their mother - apparently unable to cope - handed them over to social services for adoption. They had already been with one foster family before they were placed with the Bramleys, who had never fostered before. When the Bramleys gave them up, another set of foster parents was poised to replace them.
We may ask why children who were considered to have such special needs were placed with novice parents. The social services spokesman will only say it is "not a perfect science". But the Reverend Jack Cooper, the retired cleric who apparently spotted the family on the Yorkshire steam train, adds to a picture of parental inadequacy. He described the children as out of control, and said that the Bramleys - and particularly Jenny - looked depressed, worn-out and beaten.
The public seems to prefer descriptions from the Bramleys' neighbours, of happy, well-cared-for children.
It is four years since the naked body of little Rikki Neave, who was on Cambridgeshire's at risk register, was found in a Peterborough wood. After his mother was jailed for child cruelty, the council admitted that it had tried too hard to keep Rikki within his birth family. Another scandal occurred two years ago when the "career paedophile" Keith Laverack, a former Cambridgeshire senior social services manager, was sentenced to 18 years for assaulting children in care. Those sympathetic to the Bramleys just assume that "the bloody social workers have got it wrong again".
The prevalent public feeling seems to be that the couple's flight is an act of love, not selfishness. But Mr Nicholson appeals to people - and particularly anyone harbouring the Bramleys - to put the children first.
"The focus of the story has become Jeff and Jenny," he says. "And, yes, it is a sad story. But think of the children; their upbringing has been put on hold." Jade was due to start school in September. Her uniform is still hanging, unused, in the abandoned house in Ramsey.
At his home near Colchester, Dave Bodle, Jenny's brother, a civil servant, says that the discovery of the Honda brought the couple's worried family some brief relief.
Like the police, the family had considered two explanations for the failure to trace Jeff and Jenny. With Felixstowe, Harwich and a handful of other ports within easy reach of Ramsey, there was always the strong possibility that they had fled the country. The other appalling option was that the couple and the children were dead.
For Ramsey has a reputation for losing people. Last century the ancient Fenland settlement was a thriving port. Left high and dry by time, it now sits at the edge of hundreds of miles of deep, water-filled drains, which prevent the fens being reclaimed by the sea. If a car leaves the road, by accident or design, it can be months before the vehicle and its occupants are recovered.
Dave and Jenny were born and grew up in Bury village, now an extension of Ramsey, where their father was sub-postmaster for 40 years. The small extended family is close and private. So it was easy to contemplate the worst when Jenny, who "has never been out of contact for more than a week" disappeared without a trace.
Mr Bodle refuses to discuss social services' decision to remove the children, saying that criticism will have to come from Jeff and Jenny themselves. But he says that the couple, who had been married for 10 years, loved the Bennett sisters and were "devastated" when told that they could not keep them.
Mr Bodle, who has worked with people with special needs, says that while the children were "boisterous", they were not hyperactive or badly behaved.
"Jenny and Jeff are so quiet," he says. "So it was quite a contrast between them and the kids, but as a family group it seemed to work. The neighbours seemed to think so, as well."
He describes Jenny as bright but shy, like the husband she met when they both worked at the post office. Both, he claims, are logical and rational people. "You just would never have imagined they would do something as dramatic as this," he says. "But they found themselves in extraordinary circumstances."
He sympathises with the stress the couple have been under while trying to adopt the children. An attempt to challenge the council's decision in court failed; social services remained "judge and jury". "A friend of mine has been through this," says Mr Bodle, "and he says being under constant scrutiny from social services for six months was the worst time of his life."
Like the police, Mr Bodle thinks it is possible that the Bramleys are being helped, though definitely not by a family member. And he agrees that public sympathy may be hampering the police investigation. He has been told that even former police officers have said they would not arrest the Bramleys, but would give them money to help them on their way.
However, he says, the only real solution is for the Bramleys and the children to return home. The situation is putting them and their extended family under great stress. "Every night you go to bed thinking maybe they will come back tomorrow."
Thick curtains are closed over the front windows of the Bramleys' home on the Maltings, a private estate of modest houses crammed too closely together. Only a few neighbours were aware of the Bramleys' desperate battle with social services. As one puts it, all they saw was two lively little girls with apparently devoted parents.
Many locals share the public's ambivalence about the Bramleys' "crime". One woman thought Jade and Hannah were children from a previous marriage, until she heard them calling Jenny and Jeff Mummy and Daddy. Though friendly, the Bramleys were private; most neighbours found out that they were fostering only after their disappearance. She saw nothing to suggest that the couple lacked parenting skills. "We don't know all the facts," she says. "But the girls always looked happy and well looked after." And she adds: "What the Bramleys have done, well, it's not like a real crime, is it?"
One lawyer who specialises in child care cases wonders what will happen if the Bramleys succeed in staying on the run for a year, or even two. If the children are well and happy, and have become even more attached to their "unsuitable" foster parents, will the courts still consider separation to be in their best interests? But Cambridge social services points out that its decision to remove the children was endorsed by the courts, and it will defend that stance. The children's current lifestyle, a spokesman says, can only be doing them harm.
If Jeff and Jenny are as logical as Dave Bodle says, they have probably concluded that eventually they will have to come home and hand the children over. Perhaps in their distress they are spinning out one final family holiday (with steam train trips and other treats), clinging hopelessly to moments, and children, they cannot keep. An act of love or selfishness? Probably a bit of both.
Mr Bodle asks the Bramleys to call the National Missing Persons helpline, 0500 700 700Reuse content