When Toyota arrived three years ago in NASCAR’s Sprint Cup series it signalled the beginning of big changes for American stock car racing.

Led by enfant terrible Kyle Busch and Joe Gibbs Racing, Toyota’s teams are growing stronger by the month although Chevrolet’s top teams continue to field the drivers and cars to beat with Tony Stewart, Jeff Gordon and Jimmie Johnson currently running one-two-three in the Sprint Cup championship.

But NASCAR’s Chevy teams are bracing themselves for an announcement detailing General Motors’ cutbacks in spending as it works through its Chapter 11 bankruptcy reorganisation. The Chevrolet teams competing in NASCAR’s second- and third-division Nationwide and Truck series were informed on June 9 that they would not receive any financial support next year, although engineering assistance and wind tunnel time will still be available. A similar announcement will soon be made by GM concerning the premier Sprint Cup series.

“Chevrolet’s involvement in racing is a sound business decision that translates directly into the sales of cars and trucks,” said GM in a statement about the Nationwide and Truck cutbacks. “It is essential, however, that we look at every penny we spend as General Motors takes the necessary steps to become a leaner company.”

NASCAR chairman Brian France said: “I’m confident [Chevrolet] will be in the sport for many, many years because it works well. But, obviously, under different circumstances.”

Four factory-supported Chevrolet teams compete in NASCAR’s top series. Hendrick Motorsports fields four cars for defending champion Jimmie Johnson, four-time champion Jeff Gordon, Dale Earnhardt Jr and Mark Martin; Stewart-Haas Racing runs two cars for two-time champion Tony Stewart and Ryan Newman; Richard C

Childress Racing’s trio of Chevys are driven by Kevin Harvick, Jeff Burton and Casey Mears; and Earnhardt Ganassi Racing runs a pair of Chevys for Juan Pablo Montoya and Martin Truex Jr – 11 cars in all.

Both General Motors and Chrysler are using America’s Chapter 11 bankruptcy laws and $62 billion in bailout funds from the United States Treasury to restructure and reduce costs. GM is selling off its most troubled brands and has closed 2600 dealerships across the USA, reducing its debt by $17bn.

Meanwhile, NASCAR has been pitching other foreign manufacturers to join Toyota in the Sprint Cup series. Last week officials flew to Germany to meet with the Volkswagen Group, which has been looking at competing in the IRL IndyCar Series when its new formula begins in 2011. But NASCAR has stepped in to try to convince Volkswagen (which includes Audi and, of course, Porsche) that the Sprint Cup series would offer a much more powerful marketing platform. Brian France admits that NASCAR has been talking for many years to numerous global auto manufacturers.

“NASCAR is the pre-eminent place in North America for car manufacturers to build their business through auto racing,” he said. “We have our philosophical approach to welcoming new companies into our sport, as we did with Toyota. It is under a very clear set of circumstances that manufacturers come to NASCAR to compete and that will not change.”

It appears more likely therefore that Toyota represents only the leading edge of NASCAR’s foreign invasion. Chevrolet’s top teams are sure to continue to field the drivers and cars to beat, but Toyota’s teams are getting better and it may not be long before we see Volkswagen, or even Audi, joining Toyota in NASCAR. As the man said, the times they are a-changing.