Beatlemania rocked the United States in 1964. So did Mustang mania.

In fact, the unveiling that year of Ford's sporty new model at the New York World's Fair made automobile lovers twist and shout.

A Chicago showroom overwhelmed by would-be buyers was forced to summon police. In Garland, Tex., the winner among 15 customers who bid on the same Mustang insisted on spending the night in the car until he knew that his check had cleared. One restaurant owner advertised that his hot cakes were selling like Mustangs.

Proof of the car's enduring popularity will be on display with about 500 vintage Mustangs on Sunday at Six Flags Magic Mountain. "Mustang Magic," as the show is billed, is sponsored by the Pacific Mustang Club, one of two San Fernando Valley-based groups whose members share a passion for the Mustang.

Car owners from as far away as Bellevue, Wash., are expected to motor to the show.

But, clearly, the star of this show is a car.

"I've always loved Mustangs," said Terry Pottratz, vice president of the Pacific Mustang Club and the show's organizer. "The very first car I ever owned was a Mustang. Everyone has a theory about Mustangs and why they're drawn to them. For me, I think it's just that style and character that no other car could have."

Love your Mustang? Join the club.

There are an estimated 450 Mustang clubs in 16 countries. In the United States, there are 301 Mustang clubs and membership exceeds 100,000, the largest organized following of any car.

The Pacific Mustang Club and the Mustang Owners Club of California have a combined membership of about 800. Both meet monthly so that owners can share information and plan shows in which cars are judged on authenticity of restoration or their mechanical and aesthetic modifications.

Weekend rides are another popular club activity. On Oct. 28, members of the Mustang Owners Club plan to caravan to Hearst Castle in San Simeon.

Shows and sojourns aside, the clubs' common mission is the preservation and restoration of the Mustang, one of the most popular cars in automotive history.

"I think the Mustang's appeal is that it is America's first affordable, true sports car," said Paul Croswhite of Lake View Terrace, president of Pacific Mustang Club and owner of 10 Mustangs, most in near-mint condition. "It is versatility and economy, a combination of raw power and luxury."