Published: Nov 11, 2011 5:16 PM EST

WASHINGTON (AP) - It will be Michelle Obama and Jill Biden instructing NASCAR's best to start their engines as the racing season comes to a close in Florida.
    
The first lady and the vice president's wife will visit Homestead-Miami Speedway on Nov. 20 as it hosts the Chase for the NASCAR Sprint Cup finale, the Ford 400.
    
The two women will serve as grand marshals for the event, leading the pre-race ceremony and offering the famous instructions: "Gentlemen, start your engines."
    
The event is part of the first lady's Joining Forces program to encourage Americans to support military families.
    
The crowd will include 5,000 active duty and retired military personnel and families, and a military family will join the grand marshals as they carry out their duties.

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