Gordon Shedden is on the verge of fulfilling a long-held ambition

But so much for plans. After six years as a full-time competitor, and more than a decade on from the day he made his BTCC debut, Shedden is well aware that dreams of chequered flags can all too often end with first-corner shunts and ignominious exits into gravel traps. Or, to put it another way, the fact he goes into the final weekend of the 2012 championship with a 15-point lead in the race for the title doesn't mean he's taking anything for granted.

You can understand his thinking. Shedden was a star-struck teenager when he turned up at Knockhill in 1994 expecting to watch Gabriele Tarquini strengthen his grip on that year's championship; instead, he saw the Italian ace barrel-roll out of contention in one of the most spectacular crashes the series has ever witnessed. The sober-minded reaction to the incident would have been to settle on a career in accountancy there and then, but Shedden was intoxicated by the rough and tumble of touring car racing and the experience only strengthened his resolve to be part of it.

Hence the crack of emotion in his voice as he talks of what this weekend could mean to him. "It would be everything I've ever worked for," he says quietly. "After all the ups and downs and lefts and rights, it would be the absolute summit. It's hard to describe how much it would mean."

There is a promising trajectory in the curve of Shedden's progress with the Honda team over the past three years. In 2010, he finished third in the championship. The following year, he went one better by claiming second. Now, he goes into the last event of this year's series with one hand on the trophy already. But the hot-head the fans might witness on the track is rather cooler in his assessment of the weekend's possibilities.

"You have to remember there are still three races to go," says the 33-year-old Fifer. "There are more than 60 points available and I only lead by 15. There's an awful lot of racing to happen and the nature of touring cars means that it's going to be a tough slog. But, having said that, I think the Honda Civic will be really good round the track at Brands Hatch, and the way the rules work we should have a little more speed than we had in the last round at Silverstone."

That Silverstone round, two weekends ago, marked a dramatic transformation in the title race. Until then, it had been starting to look like a two-horse canter between Shedden and team-mate Matt Neal, but two-time champion Jason Plato, a 15-year veteran of BTCC racing, closed the gap with two race wins in his MG on the Northamptonshire circuit. Neal and independent Honda driver Andrew Jordan still have a theoretical chance of winning the championship, but the likeliest scenario is that it will be a straight fight between Shedden and Plato.

Shedden has eight race wins to Plato's five this season but his rival has been the better qualifier, claiming five pole positions to the Scot's none. It is in Shedden's favour, however, that the twists of Brands Hatch are far better suited to his Honda than they are to Plato's MG. Against that, Plato won two of the three races there last year, albeit at the wheel of a Chevrolet.

Is Shedden apprehensive? Only once in a decade has the driver leading the championship ahead of the final round failed to secure the title, but an awful lot can go wrong – very suddenly, too – in the hurly-burly of a touring car race. "People say I must be nervous, but I'm actually much more excited," he says firmly. "This is what I live for, it's why I drive and it's a position I've dreamt of being in for many, many years. I'm going there confident in the car and the team. I've got the points in the bag, and it's for everyone else to make them up.

"If it happens, it happens. Whatever will be will be. If I go into the weekend and do the best I can and leave happy with how I've performed but don't win the championship that's something I will have to deal with. But the most important thing is not to worry about anyone else and don't do anything different or special. We just have to do what we've done over the nine events so far because it has been pretty successful. I've got more points than anyone else so they've all got a tougher job. That's the way I'm looking at it."

As series leader, Shedden will have to carry an extra 45kg of ballast. Plato, as second-placed man, will have a 36kg penalty. A racing purist would argue that success is being punished, but the appeal of the BTCC format lies in close competition, and Shedden knows he just has to accept the disadvantage and get on with his job. "It's going to be tough," he says. "Every other car is lighter than mine. Qualifying is going to be really important. The general rule of thumb is that 10kg makes 1/10th of a second per lap difference in qualifying. If I've got 45 in and somebody else has nothing then the difference is the guts of half a second, which is significant."

But it may be of more importance than a couple of lumps of lead that Shedden also carries the good wishes of thousands of Scottish fans who have pinned their hopes on him becoming the first Scot to take the title since John Cleland won it for the second time in 1995.

Shedden says: "It has been amazing how many people from Scotland have been in touch to say that they're planning on coming down. It's very humbling in a way. It's not something I'm used to or expect. It's really nice that people recognise that we are trying hard, trying to win it and bring this championship back to Scotland.

"John Cleland was one of the guys who got me interested in touring cars in the first place and he's been in touch to wish me the best. He pointed out that only two Scots have ever won this title – himself and Jim Clark. It would be a bit of a coup if I could be the third to get my name on that trophy. There's nothing like being in illustrious company."