``David is a driver with outstanding talent and as a result of his actions, he is the young man I selected to fill the seat,'' team owner Jack Roush said. ``The No. 6 is obviously a very special car to me personally, and to this organization, and we are confident in David's ability to step up and get the job done.''

The car will continue to be sponsored by AAA.

Martin, who has driven the No. 6 since 1988, had planned to step back from Nextel Cup racing, but announced last week he was ending his longtime partnership with Roush to drive a Chevrolet for new owner Bobby Ginn.

Martin, currently third in the points, will finish out the season with Roush and then move to the MB2 Motorsports team to drive a 22-race Cup schedule in 2007.

Ragan, who is 20, is currently a regular in the Truck Series. He beat out Busch Series regulars Todd Kluever and Danny O'Quinn Jr., and fellow truck series driver Erik Darnell for the Cup ride.

Kluever had originally been in line to replace Martin, but he struggled in both trucks and the Busch Series. Team president Geoff Smith said recently that the job was up for grabs among the four rookies.

Ragan made his Cup debut three weeks ago at Dover, starting 37th and finishing 42nd. He is scheduled to run four more Cup races this season, beginning at Martinsville on Oct. 22.

``This is a tremendous opportunity,'' Ragan said. ``Obviously, I've got big shoes to fill and quite a legacy to follow, but I look forward to the challenge and the next chapter of the No. 6 race team.''