LAS VEGAS -- Juan Montoya's car sat in its garage stall with its hood up, and crewmen toiling underneath. Next door plastic and tape covered areas of Kasey Kahne's car that had been repaired. And next door to that mechanics worked beneath the vehicle of Bobby Labonte, switching out parts under the watchful eye of a NASCAR inspector. The whole area was filled with the whirring sound of mechanical tools and the smell of new paint.

It was that kind of day Friday at Las Vegas Motor Speedway -- hot, slick and full of unexpected and unfortunate duties for the men on the Sprint Cup tour who turn wrenches for a living. Six cars went sideways during opening practice for the UAW-Dodge 400, some surviving with minimal to no damage and some needing to be scrapped altogether. The combination of a new chassis, a hard tire and a year-old pavement forced one vehicle after another to limp into the garage.

"It's treacherous, I think more so than even the track we saw in testing with that tire combination," said Robbie Loomis, vice president of Petty Enterprises, which had to unload a backup car for Labonte after the former series champ smashed the wall. "But it's a tough chore, because it's hard to get a tire to live here. To do that, you've got to make it not have a lot of grip."

Labonte and Montoya got the worst of it, and were forced to go to backup cars after crashes. The vehicles of Kahne and Sam Hornish Jr. needed body repairs after scraping the wall. The lucky ones were Reed Sorenson and Patrick Carpentier, who each spun but avoided any contact. The trend continued in qualifying, when Johnny Sauter snapped loose and smashed up the Wood Brothers' entry. All six of the practice incidents involved Dodges, which Loomis called a coincidence.

"You look at it," he said, "and it's everybody trying real hard trying to make it do a little bit more with less."

A learning curve was to be expected at Las Vegas, the first race on a 1.5-mile intermediate track for the new car that debuted last year. Although last week's race in California was at a bigger facility, Las Vegas has higher banking and places a greater vertical load on the car. Cup drivers had plenty of issues coming to grips with Las Vegas last year, in the first race weekend after the place was resurfaced and the corner banking was increased from 12 to 20 degrees. The new car only increases the challenge.

"I think we just have less grip with this car," said Jeff Gordon, whose top lap of 179.736 mph was second-fastest of the opening session behind points leader Kyle Busch. "We put up a pretty fast number, and I think guys are just trying to push the limits and get faster and try to put down that fast lap. My car felt pretty good."

So did Labonte's, until his crew made a spring rubber change on the right-front. Suddenly he was loose, and with this car on this track, it doesn't take much for a vehicle to swing around. Before he knew it his car was into the wall, and a good car was in pieces. The line between loose and into the wall is evidently as thin as a playing card at a blackjack table.

"The grip on these tires is either there or not there," Loomis said. "If' it's loaded, it's pretty good. But as soon as it's not there, it's gone. There's no real warning."

Was Friday a preview of what to expect in Sunday's 267-lap event? Maybe not. Gordon and Loomis both pointed out that the spins and crashes in the first practice came during mock qualifying attempts.

"It's usually different when you're trying to make qualifying runs," Gordon said. "You're really committed and you're blasting the car down in there and trying to get back in the gas hard. In the race, you get a few laps to feel it out. I'm not going to say it's not going to happen [Sunday], but I would think it would happen more on qualifying day than any other day."

Fast Facts

What	UAW-Dodge 400
When	3:30 p.m. ET Sunday
TV	FOX
Radio	PRN / Sirius Ch. 128

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Bumps along the bottom of the track in Turn 1 didn't help. In such twitchy loose conditions, Loomis said, anything that upsets the vehicle is capable of snapping it around. Sunday, he expects more cars in the smoother, higher line.

"I think what you'll see in the race is, more guys will move up a lane," he said. "In qualifying everybody's trying to run the bottom and hit that bump. It's a pretty rough ride, and the suspension parts take a beating. You hit the bumps, and the cars just take off. We get to the race Sunday, it will probably settle down a little bit once everybody gets their cars driving a little bit better."

To make matters more difficult, teams practiced and qualified Friday in conditions completely different from the cold, windy ones which greeted them for a test here two months ago. Busch's top speed Friday was more than a second slower than the fastest lap set at testing, Montoya's unofficial track record of 186.761 mph.

But the test session wasn't a total waste. "You've got good telemetry on the bumps and the travel," Gordon said. "The grip level might be a little bit different, the consistency might be a little bit different, the track temperature is different. But it was still worth coming out here. I would have rather had these conditions, though."

At least Gordon's car survived the session in one piece. That couldn't be said for all the vehicles on the Sprint Cup circuit, some of which had to be massaged and hammered back into shape.

"I think what you're seeing is, some teams have got it, and some teams are way off," Gordon said. "That's kind of how this car works in the beginning stages of going to these different tracks. You're going to have some guys that have engineered all the right components and figured it out, and some guys that haven't."