Update: 'Darius' Call'

May 1, 2007 — -- "Nightline" has been following the remarkable story of Darius Weems, a teenager struggling with muscular dystrophy. Weems is the subject of a documentary called "Darius Goes West," which was shown at a special fundraising event at the Tribeca Film Festival.

Weems had many dreams, and one of them was to perform a rap before he loses his battle with the disease that also took his brother's life. With a little help from long-time music arranger Gary "Headman" Haase and vocal sound engineer Benji Allen, that dream became a reality. And I was lucky enough to participate, playing the bass and percussion on the track, which is called "Darius' Call."

The music was produced by Haase at his studios in Manhattan, Headman Music. Weems' vocals were cut by Allen at studios in Athens, Ga., near Weems' home.

Click here to listen to the track: http://a.media.abcnews.com/mp3/070501martinrap.m4a

Since the release of "Darius Goes West," Weems' life has been full of surprises.

In March, at the Atlanta Motor Speedway, he was invited as a guest of honor to the pit area where NASCAR driver Kyle Petty was preparing to race.

Weems sat trackside as the national anthem was sung, and he had no idea that a further surprise awaited him.

Mike Accavitti, director of Dodge Motorsports (part of the Chrysler group), presented Weems with a brand-new wheelchair-accessible Dodge Sprinter.

For years, Weems had been transported around in an old, battered Dodge high-top van, but with almost 200,000 miles on the odometer, the vehicle collapsed last week. The van belonged to the family of Logan Smalley, who directed the documentary "Darius Goes West."

"Darius Goes West" follows the story of Weems' first trip beyond the boundaries of his hometown. Weems and a team of friends and helpers rented an RV and drove from Georgia to California, in hopes that the MTV show "Pimp My Ride" would agree to remodel Weems' wheelchair.

In the process, they raised awareness about muscular dystrophy, a condition that remains the single biggest genetic killer of children worldwide.

When he presented Weems with his new car, Accavitti said, "Bold capability is a hallmark of the Dodge brand of vehicles and a shared attribute with Darius Weems, a young man with a vibrant spirit."

As for Weems' reaction? He kept saying, "That's so cool, that's so cool."