First the Widow Maker collided with the Midnight Express. Then the Magic Bus plowed into the Potmobile. Metal mashed Detroit metal. Rubber burned. And the crowd, which paid admission to witness the carnage, cheered another 25-car pileup well done.

"I think I got hit in the mouth by an LTD," said 30-year-old Vince Jones, nursing a split lip and a bruised elbow beside the battered hulk of the 1968 Chrysler he had driven to death Saturday night at a Demolition Derby in Manassas. "But I survived."

Survival is the only rule in the derby, a totally home-grown sport that celebrates the dark side of America's love affair with the automobile. Roll a Chevy on its hood or set a Ford on fire and the audience is yours. Forget speed and style, just keep your wheels rolling until all others have been wrecked.

"You can get rid of a whole year's driving inhibitions in one night out here," said Bob Duval, who works for C&P Telephone in Fairfax to support his passion for the auto. "It's a chance to come out here and be a great big kid. To do things you've always wanted to do on the Beltway."

Many of the drivers, who crushed more than 100 cars at Old Dominion Speedway this weekend, admitted that revenge was as much a motivating factor as winning.

Behold 25-year-old Mark David, who towed his 1965 Oldsmobile (eight miles a gallon) from Arlington to Old Dominion. He was ripped off when he bought the heap, said Davis, and soaked for a fortune in repair bills during the year he owned it. Saturday night was his big chance to squeeze some return from his investment.

"I thought I'd get rid of it the easy way," said Davis, standing beside his ghost-grey Olds, which had been renamed the Mad Dog Express for the night.

"I'm sure a lot of guys are here to work out their agressions," said Dick Gore, the general manager of the 30-year-old track built by his father and staffed by a dozen family members.

The first person to recognize the profit-making potential of car crashes was Larry Mendelsohn, who began promoting demolition derbies at his Islip Speedway on Long Island in 1958. Four years later, ABC-TV's Wide World of Sports put the spectacle on national television and the boom began.

"The biggest thing in America, what this entire country is based on, is the automobile," said Mendelsohn eight years ago. "People absolutely love to see them crash. Whenever there's an accident on a corner you have a crowd gather around. You can imagine what the crowd would be like if there were 100 cars, all in one night, deliberately crashing against one another."

Saturday night's crowd of 3,500 was evidence of local interest in motorized mayhem, particularly because the Old Dominion show was competing with another demolition derby in Dorsey, Md., the same night.

"I guess the demolition crowd is like football fans," said driver Bud Urbani before the crashing commenced. "They want to see things get all tore up."

Urbani, a 28-year-old District roofer, is the son of Lawrence "Mouse" Urbani, a Manassas mechanic and local demolition legend. The elder Urbani built cars that won four national championships during the last decades. Mouse retired two years ago, but still attends the current derbies, to talk about old times.

But Urbani's partner is Billy Pearson, the owner of a Fairfax County towtruck business. Together the two have dominated the local demolition competitions.

"In the last three years we've only lost one," said the 33-year-old Pearson, who brought a separate car for each of the four heats as well as two more for the final championship round.

"Yeah, and I'm the one that beat them," snorted Roy Rasmussen, a 25-year-old auto painter from Fairfax County who admitted that he would rather eliminate the "syndicate" of Pearson and Urbani than win himself.

While Pearson's pack set up in one corner of the infield, Rasmussen and his friends, who claimed to have 18 cars entered in the various heats, established camp in the opposite corner.

While the audience cheered the general destruction, the two opposing camps kept more particular score. Cars caught on fire. Cadillacs were crushed by Chevrolets. After two hours, eight cars had qualified to crash it out on a strip asphalt 120 yards lond and 15 yards wide for the championship and $500 in first-prize money.

"I know they're out there to get him," said Pearson's girlfriend Vivian Huffman before the finale, which both Pearson and Urbani had qualified for by winning a heat.

With the track cleared of wrecks, the eight cars had more room to maneuver and gather speed. While the rest of the field battered one another indiscriminately, Pearson and Urbani worked together, pinching a multi-colored Ford Galaxie against one wall, then peeling off to batter a Plymouth station wagon against another.

After 15 minutes, only three cars remained. Pearson and Urbani drove two of them, leaving 32-year-old Claude Shifflett and his 1968 Chevy station wagon at a decided disadvantage.

Despite the teamwork, however, Shifflett managed to outmaneuver both Pearson and Urbani. When the smoke cleared, Shifflett's Magic Bus was the only car still moving.

"I waited three years to see this," said John Patton of Woodbridge, joining a mob of drivers who rushed to congradulate Shifflett for knocking off the "syndicate."

While that scene was still being played, Mark Davis was giving his unrecognizable Mad Dog Express one last kick in the fender.

"This is all that's left of it," said Davis, walking away with a windshield wiper, a bent radio antenna and a hubcap. "Next time I'll fix up a car and really do it right." CAPTION: Picture 1, Claude Shifflet is congratulated after winning $500 first prize at Demolition Derby in Manassas; Picture 2, Speed and style aren't important, the object is simply to keep rolling until all other cars have been wrecked. Above, cars roar into each other in reverse during elimination heats.; Picture 3, Smoke swallows burned-out competitor in sport celebrating dark side of American love affair with car. Photos by Fred Sweets -- The Washington Post