"Roll up your window!" Dianne Dukelow yells at me as a pebble-faced young man approaches our black 1997 Ford Crown Victoria. "I don't know if he has more stuff to throw."

Normally, Night Avenger assignments do not entail getting pelted with food. But when the vehicle you're riding in is hitched to a flatbed trailer carrying a 12-foot glowing statue of George W. Bush festooned with a sign reading "Pants On Fire," normal rules do not apply.

As the stop light turns green, the youth turns around and quarter-moons us, the sight of his grungy white boxer-briefs eliciting cheers from his compatriots.

"Was he angry because he thought the statue was anti-Bush or because he thought we were pro-Bush?" Dukelow asks. I point to one of the laminated placards taped to the dashboard to shepherd volunteer drivers through standard operating procedures: "Do not put the words 'Liar Liar' on the mobile," one sign reads. "We're trying to be subtle."

Maybe a little too subtle.

Two weeks ago, on a quiet, frosty Sunday night, Dukelow and I became two of the dozen or so volunteers who took the luminescent party car for a presidential joyride during its 14 days in and around Portland. The car is currently barreling down I-5 to Eugene.

The craft, which features a reader board that displays "lies" told by President Bush, was built by Ben & Jerry's co-founder Ben Cohen. He created the towering monster machine in 2003 and a second last June to act as mobile shock troops for TrueMajority, his grassroots education and advocacy project. Since then, the Georges have cruised more than two dozen states, while more than 400 people have taken a turn at their wheels.

Dukelow, a 49-year-old Beaumont neighborhood resident who works with veterans, signed up to drive because she's seen veterans' benefits "go down the tubes" since Bush's policies took effect.

"[The vehicle] is theater, it's creative campaigning," she says. "And it's jerking off a few Republicans. I like that."

The "Pants On Fire" mobile may have once been a plush ride. But now the leather seats sag, the American flags on its fenders are frayed and the CD player, which comes with a selection of '60s-era protest music, is on the fritz. King George, or "the giant dildo," as a few cheering passersby call the sculpture, had a fog machine, too. But somewhere between Long Island and Portland, the apparatus got busted.

"He's had a long drive," Dukelow says as she maneuvers the rig around a corner like a long-haul trucker. "It's great to cheer people up. There's so much anxiety about this race."

She just sneers when a rotund man on the sidewalk in front of the Cabaret men's club downtown flips her the bird and makes like he's firing an invisible machine gun at us. "I'm from New York," she says. "What's a few fingers?"

But any reaction, be it a thumbs up from a pair of bagpipers or an aghast scowl from a woman eating dinner on Northwest 21st Avenue, is gratifying. It means people, if you wanna get political about it, are engaged.

Only one phrase can adequately describe the response to this party car, and it's cribbed from King George himself: shock and awe.

Check out www.pantsonfire.net for more information.