Wheelies Galore : Hobby: 150 enthusiasts gather for the annual Hot Wheels convention in Buena Park and wander hotel rooms in search of the perfect toy.

BUENA PARK —  For $500 to $600, Michael Strauss may be willing to sell his vintage Volkswagen bus decorated with brightly colored flowers typifying the 1960s, with two surfboards sticking out the back window.

But don’t expect to drive this car. It has no engine and is just a few inches long.

It is a rare toy that Hot Wheels enthusiasts would eagerly bid on if Strauss, 47, were ever to auction it off. But the collector from San Carlos in San Mateo County said he will probably never sell it because it means too much to him.

The bus is one of several rare models from his Hot Wheels collection--which numbers 15,000 miniature cars--that he proudly displayed Saturday during a Hot Wheels convention held this weekend in Buena Park. Mattel Inc. makes Hot Wheels under that trade name but does not sponsor the convention.

Many of the 150 Hot Wheels enthusiasts gathered at the fourth annual convention’s headquarters hotel and traveled from room to room Saturday to view models, hoping to find that one car that might be someone else’s extra piece but is the just the model needed for another collector’s set.

“It’s no different than collecting barbed wire or Avon bottles,” said Rock Cramer, 54, a retired Army officer from El Paso, who has been collecting Hot Wheels since 1968, when they were first produced.

Especially coveted are the extra-special cars, dune buggies and trucks that these grown-up kids are willing to trade, buy or sell for hundreds of dollars. They may be more valuable because they are older, were produced in limited quantities or even because of the manufacturer’s error.

Cramer pointed to a Shell gasoline tanker that is painted orange even though the trucks are supposed to be yellow.

“So in 10 or 15 years from now, that orange tanker may be a good one,” worth maybe $100 to $300, he said.

Attending his first show was George Dolmat, 31, a electronics designer from Montreal who began collecting the models three years ago when he bought some for his son.

He said his son is allowed to play with the cars from the collection, but the boy has to be careful not to scratch the models.

“He knows those are Daddy’s cars and to be nice to them,” Dolmat said.

Dolmat said he even tried to get insurance for his 900-model collection, but the company said, “You can’t do it because it’s something you can’t put a value on.”