It used be that wayward teen-agers got their thrills stealing hubcaps.

But in an age in which designer names appear on everything from jeans to chocolate, some teens in the area have turned to stealing hood ornaments, particularly the elegantly styled logos of the Mercedes-Benz and Cadillac.

"It's a fad, like stealing hubcaps," said Officer Ken Rosenberg of the Arlington Police Department. "They wear {the ornaments} around their neck and show them off to their friends."

According to area police and car dealers, there has been a marked increase in recent months in the number of reports of stolen hood ornaments. There also have been reports of stolen nameplates.

Fairfax County police in Mount Vernon, an area that has been hard hit with such thefts, say they have received about 40 reports of stolen hood ornaments since March.

Prior to spring, there had been only isolated reports of stolen ornaments, police said.

Other area police departments said they are aware of a trend but don't keep statistics specifically on the theft of hood ornaments. They add that many car owners choose not to report such incidents and that youths wearing the ornaments may have legally purchased them at car dealerships.

The thefts generally take place on weekend nights in residential areas, though thefts have been reported from car dealerships and school parking lots, said police.

Few cases are prosecuted because it is difficult to prove which car an ornament came from, said Rosenberg.

Lou Kappert, general manager of HBL Inc., a Vienna car dealership that handles Mercedes-Benzes, Porsches and Audis, said he's noticed an increase over the last few months in the number of people requesting replacement ornaments, which cost about $20.

"It probably started last year," Kappert said of the interest of teen-agers in hood ornaments. "But we've had a rush of incidents in the last few months."

Fairfax police said the fad for hood ornaments may be related to the popularity of certain rock music groups.

Fairfax police pointed out that a member of the New York City-based rock group the Beastie Boys wears a hood ornament around his neck, and speculated that the group's appearance this spring may have triggered a rash of thefts in the Mount Vernon area.

"I think it's a punk rock fad," said Dana Lawhorne, a youth services officer with the Alexandria Police Department.

Bill Adler, publicist for the Beastie Boys, said the group can't be blamed for the thefts, although vocalist Mike D does wear a Volkswagen ornament.

"Nobody in the group has worn a Mercedes" ornament, said Adler. "I think it's a spontaneous thing and a measure of the elitist taste of the kids perpetrating" the crime.

Police and car dealers said the most popular hood ornaments are those on the Mercedes-Benz, followed by those from Porsches and BMWs. One reason for the popularity of the Mercedes ornaments, said police, is that they are relatively easy to remove.

In one case Lawhorne said he found a box full of ornaments from Cadillacs and Oldsmobiles, most of which had been stolen from a car dealership.