Any of 41,000 fans could tell you that on Monday 'N Sync sweated and shimmied through the D.C. stop of its "Pop Odyssey" tour. But for deeper analysis, let's consult the experts on the 'N Sync Fan Bus, which as it happens isn't a bus at all. It's a 32-foot-long recreational vehicle with a kitchen, a shower, two TVs, a VCR, a queen-size bed and piles of light-blue shag carpeting.

This is the temporary home of Meredith Sandberg, 21, and Winter Byington, 22, a pair of chirpy and fiercely determined young ladies from Utah who in recent months have crisscrossed the country in this six-miles-per-gallon shrine, bivouacking at all but one of the 39 stops of the tour. They're still miffed about missing that Tampa show.

"It's because we got a flat," says Meredith, shaking her head, chagrined by the memory.

After the concert at RFK Stadium on Monday night, Meredith and Winter sat for an hour and explained how they ended up shadowing their favorite group in a $70,000 hunk of California-made steel. Last fall they hatched a simple three-part plan. (1) They would send away for tickets to the television game show "The Price Is Right." (2) They would be contestants on "The Price Is Right" and one of them would win a 32-foot RV. (3) They would drive that RV around the country and follow 'N Sync on tour.

That all of this would happen, just as imagined, seems almost ridiculously implausible -- though they have a videotape of the game show that they'll happily play for skeptics.

On it you'll see Meredith, wearing an "I'm 'N Sync with Bob" T-shirt and scampering down the aisle, heeding the timeless call to "Come on down!" In the span of about three minutes, she wins a color TV, then a can of sliced beets, then a wood-burning stove . . . and then a curtain rolls back to reveal a Fleetwood Flair recreational vehicle. The crowd shrieks; Meredith bounces up and down. Fortune is just about to kiss her square on the lips.

"I saw the wheel of that thing and I just knew what was coming," she says.

When Bob Barker asks for the missing number in the price of the vehicle, shown as $69,_80, she correctly says "five" -- because, as she explains now, there are five members in 'N Sync. With bells ringing and the crowd screaming, Winter leaps from her seat and begins a sprint to the stage, sailing past a security guard. "I just pushed him out of the way. There were tears rolling down my face," she recalls.

Their parents dragged them to a financial planner, who urged the team to sell the RV and invest the proceeds. They listened very politely and firmly declined, deciding instead to drop out of the University of Utah and scrounge for the $5,000 they needed to register the Fleetwood and drive it off a Salt Lake City lot. They planned to fund their journey courtesy of corporate sponsors, selling display space on their RV and prominent mentions on their Web site, nsyncfanbus.com. That, however, hasn't panned out.

There was a burst of interest after MTV featured their Flair in May, when 'N Syncers Lance Bass, J.C. Chasez and Chris Kirkpatrick dropped by to stir up excitement about their latest album, "Celebrity." The group eventually kicked in $5,000 to help the women out, and fans have been knocking on the door and handing over groceries and cash donations. It's unclear, though, how long the pair's reserves of cash will hold out. Spirit-lifting sticky notes are now pasted all over the RV. One says "We will get more than enough $$$!"

Meredith and Winter were sitting in the RV's upholstered seats after the show, signing the occasional autograph and gushing about the evening. The world's most popular band had just finished stirring this mostly 12-year-old crowd into a yelping, throat-shredding mass with a show as bright and obvious as a cartoon. They had gone through a few racks of costumes, including the bowlers and vests of silent-screen film stars, and later, space-age track suits that seemed plucked from a video game.

They danced and harmonized with uncanny accuracy on hits like "Space Cowboy (Yippie-Yi-Yay)" and "Pop." (It's hard to imagine that all of the vocals we heard that night were live, rather than recorded.) The fellas were lifted and lowered on brushed-steel catwalks, and later slid along a zip wire strung from the top of the stage to a midfield station. For other songs, they hopped on and off an airport-style moving walkway on the stage that zoomed them from one side of the stadium to the other.

The show was garishly colorful and paced for a crowd that takes its pop with four lumps of sugar. The music blended heaping scoops of hip-hop, soul and electronica, ending with a hard-to-follow story about a superhero named Mobius 8. There were plenty of videos to cover for the time when the group changed costumes, most of them self-aggrandizing looks at 'N Sync's staggering success.

So how did the D.C. show compare with others? And do 'N Sync shows differ from city to city?

Not much, it turns out. "It's the same set list, and they say the same things between songs," says Meredith. "Sometimes they change shirts."

"They seldom change anything," says Winter. "We love it, though. It's like listening to your favorite CD over and over."

Was there anything about the Washington show that was unique? There was a moment, midway through the show, when the band made time for a roadie to propose to his girlfriend. Surely that was new.

"Oh yeah, that was different," says Meredith. Then she thinks of something else. "Actually, Justin did this new move. A new dance move."

"Yeah," adds Winter. "We were going crazy."

Winter Byington and Meredith Sandberg of Utah may be 'N Sync's biggest fans, and they certainly have the biggest fanmobile: a 32-foot motor home that they won on "The Price Is Right" and drove here for a concert Monday at RFK Stadium as part of the band's -- and their own -- "Pop Odyssey." They missed only one tour stop out of 39, because of a flat tire.'N Sync fans Winter Byington and Meredith Sandberg in McLean with their motor home away from home.