DAYTONA BEACH, Fla. - Jimmie Johnson's quest for a fifth straight NASCAR championship will begin in a backup car.

Johnson was involved in the latest wreck at Daytona International Speedway yesterday, doing enough damage that crew chief Chad Knaus decided to scrap the primary car for Sunday's season-opening race.

"I was just riding along and thought everything was fine, and the next thing you know, I was in the middle of it," Johnson said.

Joey Logano and Kyle Busch also got caught up in the accident during the second practice at Daytona International Speedway. Mike Bliss triggered it when he lost control of his car coming out of a turn. Bliss turned sideways, seemingly got tapped by Derrick Cope, then shot across the track and rammed into Logano.

Logano also was forced into a backup car. Busch's car sustained minor damage, and he was back on the track a few minutes later.

The two practice sessions had several other harrowing moments.

Clint Bowyer started a three-car accident in the first session when he cut a tire, hit the wall and collected David Reutimann and 1990 Daytona 500 champion Derrick Cope. Bowyer and Reutimann went to backup cars.

Two-time Daytona 500 winner Michael Waltrip and fan favorite Dale Earnhardt Jr. narrowly avoided wrecks in the second session. Waltrip spun and drove through the infield grass, but managed to not hit anything. Earnhardt got a little sideways after getting bumped from behind by Denny Hamlin, but Junior got the car straightened out at 190 mph.

Earnhardt said over his radio that Hamlin "doesn't know how to bump draft."

"I think he made an aggressive move with [Jamie McMurray] and I followed him," Hamlin said.

Last month, NASCAR relaxed its rules on bump-drafting and gave drivers permission to be more aggressive.

Noteworthy

* Michael Waltrip said the Daytona 500 may not be his last race, after all. Waltrip said he is close to lining up a sponsorship deal to run April's race at Talladega Superspeedway. He is stepping away from full-time racing to concentrate on being a team owner, but was hoping to still compete in some events.

When sponsorship didn't materialize, Waltrip came to Speedweeks believing Sunday's season-opening Daytona 500 would be his last race. Waltrip has three wins at Daytona - two in the 500 - and one at Talladega.