Carl Edwards has earned seven top-10 finishes in eight starts at the Michigan International Speedway. Drew Hallowell/Getty Images

SI.com's Mark Beech offers the most intriguing news, notes and analysis fans s need to know heading into each week's race.

GREEN FLAGS

NASCAR takes its show back to Michigan International Speedway this week, and while I'll be as curious as anybody to see if Carl Edwards or Jimmie Johnson (or maybe Dale Earnhardt Jr.) can beat Kyle Busch, there's something else that will bear watching. And it won't be on the track.

How many empty seats will fill the MIS grandstands this Sunday?

With the economy stumbling its way forward under the weight of high oil prices, NASCAR has some serious issues to deal with, and attendance is the most visible one of all. When I was at Michigan last June for the LifeLock 400, the big news from the race was that Junior had finally found his way back to Victory Lane.

But the indelible memory that I took from the track that day was the sight of a vast swathe of empty seats running through the crowd. In the past, no matter what was going on in the world, NASCAR could bank on a sellout at MIS. But no longer. Given the choice between watching the race on television and driving out to see it in person -- and thus spending in the neighborhood of $60 to fill up on gas at least once -- the average fan opted for the couch. Little surprise then that television ratings for the race were up from last year.

But attendance isn't the only troubling sign. A sluggish economy affects just about everyone, including NASCAR's corporate sponsors. Current exclusive sponsorship deals run about $20 million per year, which is one reason we don't see as many of them as we used to and the only reason why there are no new sponsors coming into the sport. Even DuPont takes a few races off from appearing on Jeff Gordon's No. 24 Chevy. And several cars are backed by more than one sponsor at the same time, such as Little E's No. 88 Chevy, which is why the National Guard and Amp Energy Drink have a co-financing deal with Hendrick Motorsports.

Last week, a member of one of Cup racing's top teams explained the problem. "Teams in our sport will do whatever it takes to win," he said. "If the sponsors gave them $30 million, the would spend it all. If they gave them $200 million, same deal."

And that gets us to the backing from manufacturers. Once part of the very essence of NASCAR, the auto-makers' imprint on the sport is almost nonexistent today, with the new cars of Ford and Chevy being indistinguishable from those of Dodge and Toyota. Take the Chevy bow-tie off of Jimmie Johnson's car and replace it with a Ford insignia, and there's probably only a handful of fans in the world who could tell the two cars apart. This condition is especially odd in the context of a race at Michigan, which in the past was always a race the manufacturers freighted with special significance. Where better to show your clients a good time?

But not anymore. This season, the struggling General Motors corporation, has openly discussed pulling back some of its support for NASCAR's Chevy teams. How long will it be before auto-makers take a long, hard look at the Craftsmen Truck series? Who's going to buy a truck -- and advertising trucks is the only reason the circuit exists in the first place -- with gasoline at $4 per gallon? Truck racing is some of the most entertaining racing in NASCAR, but that fact alone might not be enough to save it.

Some of these problems will go away in time as the economy recovers. Attendance, while noticeable, doesn't appear to be a long-term thing. But the high-cost of sponsoring a team is not coming down anytime soon. And the Car-of-Tomorrow is a fact of life now and into the future. At some point, NASCAR is going to have to give its biggest sponsors more return on their investment.

HOW TO DRIVE

Michigan International Speedway

Tony Stewart talks about the D-shaped oval at MIS: "The thing about Michigan is that it's been there for so long now that there's no one, specific groove anymore. You can literally race from the white line on the apron all the way to the wall. That's the groove. Depending on how your car is driving, you can move around on the race track and help yourself. That's what makes Michigan such a fun race track for the drivers. The drivers can really help themselves out if they don't have a car that's working right. You can move around on the race track and find a spot that helps your car do what you need it to do."

PIT STOPS

7: Top-10 finishes in eight starts for Carl Edwards at Michigan

7.3: Average finish for Edwards at Michigan, the best among active Sprint Cup drivers

112.5: Driver rating for Edwards at Michigan, the best among active Sprint Cup drivers

MICHIGAN MEMORIES

August 20, 1978: David Pearson wins for the ninth and final time at Michigan, holding off Cale Yarbrough and Darrell Waltrip to prevail in the Champion Sparkplug 400. Pearson's victory closes a 10-year, 18-race run at MIS that saw him win nine races and finish in the top five 16 times.