Could a London Grand Prix ever take place?
Few things in sport are guaranteed to generate publicity like someone high-profile in Formula 1 talking about running a grand prix around the world-famous sites of central London.
After all, what's not to like? Who doesn't think it would make one of the most spectacular sporting events the world had ever seen?
That's clearly what the PR agency which represents one of McLaren's biggest sponsors was thinking when they invited the media to a lavish event at London's RAC Club on Thursday to hear Lewis Hamilton and Jenson Button talking about what it might be like to race around such a track.
An expensively produced video was played. Hamilton and Button said all the right things - while being careful not to be seen in any way to diminish the importance of Silverstone as the home of the British Grand Prix.
And a virtual race was staged around the track with teams led by the McLaren drivers featuring Rio Ferdinand, Melanie Sykes, Olympic gold medal winner Amy Williams and Radio One DJ Sarah-Jane Crawford.
All in all, an effective way to generate a bit of extra media coverage ahead of next weekend's ninth round of the world championship at, yes, Silverstone.
In what will doubtless have been fantastic news for the PR agency and sponsor in question, though, the story developed a life of its own even before the event was held, when F1 boss Bernie Ecclestone was quoted in a newspaper saying "maybe we would front it and put the money up for it".
A London race would see the drivers go past a number of iconic monuments.
Within F1, the idea of a race in London in such circumstances has been greeted with intense scepticism. "Of course it's not going to happen," one senior figure said on Thursday. "You know that, and so do I. But it makes a great story, doesn't it?"
On the back of it, there was an inevitable media whirlwind.
The mayor of London, Boris Johnson, was asked about it, and said he was "broadly positive providing we can satisfy the air quality and noise issues".
Which, of course, they never could. So, apart from the fact that it's a PR stunt on which Ecclestone has chosen to offer an opinion, that's the first reason why it is unlikely ever to happen. There are many more.
Before we get into those, however, it is worth mentioning that Ecclestone has tried to make a London Grand Prix work before.
In the mid-noughties, he discussed it with Johnson's predecessor Ken Livingstone and the Live Aid promoter Harvey Goldsmith, focusing on the two biggest hurdles - money and logistics.
Holding such a race would mean closing off part of central London for at least three days and disruption for much longer as preparations were made. There is an inherent cost in that.
Then there was Ecclestone's fee, setting up and securing the circuit, sorting out infrastructure, policing and so on.
On the plus side, a grand prix would showcase London and boost the city's profile, and probably - all things taken into account - bring in more money than it cost. Not that London, as one of the three biggest tourist attractions in the world, needs any extra publicity.
Five years ago almost to the day, I asked Ecclestone about these very plans. "I spoke about it with the mayor a couple of years ago, I think," he said. "He was very supportive. But we came to the conclusion that it would be too expensive."
A source close to Ecclestone expanded on that. "Bernie put a lot of effort into it," he said. "He said they looked long and hard at it and they couldn't make it work.
"There was very little money forthcoming from Livingstone, so it had to be self-supporting and they needed a way of getting people in.
"But there was only room for 30,000 people and, with the money they needed to pay to put it on, that would have meant charging £500 a ticket."
Damon Hill, then the president of the British Racing Drivers' Club which owns Silverstone, added that he had spoken "to Harvey Goldsmith about it a while back. I think it's dead. Logistically, it's a non-starter."
Which brings us back to the hurdles. The first being the idea that Ecclestone would put up the money for it. That's not how it works - venues pay a huge fee to the commercial arm of the sport, which Ecclestone runs, for the privilege of hosting F1.
That's not to say that F1 stumping up the money to host a race is a bad idea. Quite the contrary - some senior figures in the sport believe that's exactly what it should do to establish itself in America.
There is no market F1 wants to crack more than the US but last autumn Ecclestone played a game of brinksmanship with this season's new race in Austin, Texas, saying it would not be put on the calendar unless it paid its fee.
A similar situation seems to be developing with the proposed race in New Jersey overlooking Manhattan - an event F1 needs much more than one in London.
Then there's the fact that Britain already has a very popular grand prix at Silverstone, which has a contract until 2027, with a break clause either side can exercise in 2020.
With countries apparently queuing up for races - Russia is due in 2014, Mexico is also said to be imminent, Thailand is keen - the idea of holding two races in one country is seen very much as a thing of the past.
Equally, this is the second idea for a London Grand Prix that has come up in the past six days - on Friday another newspaper reported plans for a race around the Olympic Stadium.
Asked about this by BBC Sport at last weekend's European Grand Prix, Ecclestone said: "We're talking."
Hardly a surprise, is it, that F1 is so full of cynics?
In F1 - especially where Ecclestone is involved - one learns to never say never. But in a nutshell, what of the London Grand Prix?
Great PR coup? Yes. Likely to happen? Don't hold your breath.