by Lee Spencer

Drivers who have a tendency to push each other in non-drafting zones — entering, throughout and exiting the corners — could make contact with a car that's at an awkward angle and send it spinning into the wall.

"For a long time now at Daytona and Talladega, we've warned the drivers about aggressive driving, and we will do that again for tomorrow's race," said John Darby, NASCAR Sprint Cup Series director. "But, more importantly, what doesn't make sense is to let aggressive driving go unnoticed or with no reaction in practice, where everybody's there to shake their cars down, dial them in, get them ready for the race.

"To ignore that and have the potential of a big wreck in practice, to where the teams have to go and scramble for backup cars, didn't make sense. What we saw early on in practice yesterday was that everybody was getting a little carried away, and at the start of the second practice, we warned them, just said to relax a little bit and do what they needed to do and stay off the aggressiveness."

Darby contends Michael Waltrip did not heed the warnings during Happy Hour when he was riding the bumper of the No. 48 Chevrolet of Jimmie Johnson.

So NASCAR elected to black-flag the No. 55 Toyota.

Series points leader Johnson didn't see a problem with the drafting in practice. According to the three-time champ, he was simply testing moves with a potential dancing partner.

"We were running along trying to figure out how to push people throughout the day from me pushing other cars and other cars pushing us," Johnson said. "And I don't know if it was just the combination of his car and ours, but we got hooked up and started flying.

"So I certainly hope to find him in the race, and I'm glad we found that out."

Kasey Kahne found a similar partnership with Denny Hamlin in practice. Kahne's crew chief, Kenny Francis, is concerned NASCAR won't allow the push-drafting during the Amp Energy 500 because when two cars hook up, the pair can pull away considerably from the field.

"Any two cars that can get together and push each other, it's like having one car with two engines," Francis said. "If the drivers discontinue the push, it breaks the draft and the cars lose momentum through the corners so you can't have as fast of a lap time."

Johnson and Waltrip actually discovered their compatibility in the spring Talladega race last year. Johnson was pushing Waltrip on the white-flag lap when the No. 55's engine failed.

Darby's warning over the radio during practice caught the competitors' attention. Johnson said he's "a little curious to see" how NASCAR will police the race and what the actual no-drafting zones will be.

"That's the first time they'd parked the car in practice for push-drafting," Johnson said. "We've seen aggressive drafting and bump-drafting and somebody would be penalized and they'd bring them to pit road and make them think about it.

"But that's the first time I've seen it from a pushing standpoint. And as the leader and somebody is pushing you, there's not a lot you can do. I certainly wasn't going to let off and let him run over the back of me."

And so the pushing continues. Hamlin has discovered he can push-draft a car in front of him for two full laps before his water temperature pegs. Fabricators reinforce the noses and tails of restrictor-plate cars with the intent of taking a beating.

But NASCAR's concern is more about where the drafting takes place and the potential volatility.

"If you look at the pushing, if you look at the bump-drafting, if you look at the blocking — if you look at all of it — the cars stand a lot better chance staying under control when they're going straight, down the back straight or even down the front straightaway," Darby said.

"When cars are turning corners, a little of that goes a long way, and what we did see yesterday was a couple instances of somebody pushing a car or bump-drafting and getting carried away with it too deep into the corner to where the front car actually got sideways in practice."

The boys in the tower will be monitoring the situation closely throughout the race. Certainly, race director David Hoots will repeat the infamous pre-race words recited at Daytona and Talladega, "Drivers, this is your warning ..."

But on Sunday, the competitors also need to understand where the zones are and what the consequences will be.

Whole lot of shaking going on

Goodyear received numerous complaints from drivers regarding vibrations with the tires.

"We've had some people that have reported unexplained vibrations on the racetrack," Goodyear engineer Rick Heinrich said. "We went through and rechecked the balance on the assemblies and haven't seen an explanation in terms of balance. We've rebalanced some (tires) and the teams that went back on the racetrack found the same vibration.

"We're still looking at it trying to find an explanation from a wheel/tire standpoint, but we haven't found one."

One tire specialist said since the track was repaved three years ago, the smoothness of the surface has offered a greater awareness of the car to the drivers. Heinrich concurred that complaints have increased since the repaving.

Filling seats

Truck Series rookie James Buescher will drive the No. 1 car starting with the Nationwide Series new-car test on Monday at Talladega as well as the upcoming races at Texas Motor Speedway and Phoenix International Raceway in preparation for a full-time gig in 2010.

Buescher finished 15th in Saturday's Mountain Dew 250 and is 14th in the point standings.