Ambrose joins MWR for Atlanta

MWR is set to replace the No.00 car with Ambrose's No.47 for the final four races of the season, following bad results for the entry which was driven by rookie Michael McDowell for most of the season.

The Toyota team had already committed to a technical partnership with JTG Racing to field a car for Ambrose full-time next season, but given the lack of results of the No.00 entry, the switch has moved forward.

"It's really nice to have a head start on 2009 and integrate Marcos with our team," Waltrip said. "We're pleased that NASCAR worked with us to switch our number so that Marcos and his sponsors have continuity.

"I, of all people, know the importance of car numbers to sponsors. We're very appreciative that everything worked out. This is a great opportunity for Marcos and it gives him a glimpse of what next season may look like for him. We are really happy about that."

Ambrose has made seven starts this season driving Fords for Wood Brothers and JTG Racing, scoring a third place at Watkins Glen in August.

The former Australian V8 Supercar champion has yet to be confirmed by MWR for the three races after Atlanta, but he is expected to drive a Toyota for the reminder of the season.

"It's a privilege to have the opportunity to come to Michael Waltrip Racing," Ambrose said. "There is a lot of synergy here and I'm looking forward to qualifying the No.47 Toyota.

"Racing with the organisation gives me the chance to have an early start on getting to know my team, Michael Waltrip and how the company operates."

Ambrose's best result in an oval race came at Indianapolis, where he finished 22nd in his first outing at the Brickyard after qualifying on time.