Allan McNISH once remarked that there were three races which should be on every racing driver's to-do list:

the Monaco Grand Prix, the Indy 500 and Le Mans. And the time was when such talismanic individuals as Dario Franchitti, David Coulthard and McNish himself used to bask in the heady afterglow of victory at these prestigious venues.

Times have changed and there will be a conspicuous absence of Scots, either in Monaco or Indianapolis this weekend or at the fabled French circuit next month. The cupboard is not bare, but there are definitely problems and most of them relate to sheer hard cash.

Susie Wolff knows about the finances which inhibit dreams as much as anybody, but, to her credit, the Oban-born test and reserve driver with the Williams F1 team has transcended every obstacle placed in her path. Only last week, she competed in a test in Barcelona and finished fifth in the standings, which prompted raised eyebrows among the European media, because one of those whom she trumped was the reigning world champion, Sebastian Vettel.

Wolff, as pragmatic discussing her prospects as she is knowledgeable about her milieu, refused to read too much into her success, and expects life to be a lot tougher when she becomes the first-ever woman to take part in full-blooded qualifying sessions at the British and German GPs in July. But she admitted to being surprised when I mentioned the absence of any other Scots at these blue-riband events.

Then she ran through some extraordinary figures. "It's quite alarming, because we have grown used down the years to seeing Scottish drivers at the centre of the action, but life is getting tougher and tougher and that applies as much to Formula One as it does anywhere else," said Wolff.

"The fact is that very few drivers are making large sums of money these days. You have a few superstars [men in the mould of Vettel, Fernando Alonso and Lewis Hamilton], who are well rewarded, but then, they have all won world titles. Then you have the middle ranked drivers who are getting by, but are certainly not able to dictate terms as used to be the case. Then you have the guys who essentially buy their race seats and make nothing from the sport. It's very tough.

"If you don't cut the mustard, there might be 20, 30 people waiting to seize your place. It's not like football, where all you need is a pitch and a ball.

"There are ways of helping people. The Motor Sport Association set up a Rising Stars programme, and somebody such as [Thornhill's] Ross Wylie has benefited from that and is doing well in the GT Championship.

"But we're no longer talking about keeping going with a few thousand here, a few thousand there. A season in [the second-tier] GP2 costs €2m - where do most folk get that type of cash?

"Even if you look at the F3 circuit, you are talking about maybe €750,000 a year to be competitive. You can look for as many sponsors as you want, but the reality is that the majority of people can't afford it."

It is not simply at an elevated level where spiralling costs have stifled ambitions. Kyle Fowlie is one of Scotland's best karting prospects and wants to advance further. But, as his uncle, Roy Geddes, explained, it's a gruelling struggle. "Last weekend, at Buckmore Park in Kent, Kyle won the senior class and Sandy Mitchell won the junior class, so the driving talent is available in Scotland," said Geddes.

"But it was noticeable how few Scottish drivers competed in the finals of all the classes. Out of 120-plus drivers, just six were Scots.

"It is proving impossible for our elite drivers to progress through to the higher levels. If you look at the grid in Formula 4, which is the next stepping stone for karters, most of the participants come from overseas.

"Unless a family is very wealthy, the majority of the karters drop out of the sport and that happens in every level of motoring. France takes a different view and their Formula 4 series is subsidised for the local French drivers who are given financial and technical support in their preparation for events."

It is not rocket science. If there is not the investment, there is little prospect of the current downturn being transformed.

In which case, we had better enjoy Wolff's victories over Vettel when we can. The chances are they might become ever more rare in the years ahead.