LÜDENSCHEID - There aren’t many places more secretive nowadays than a certain German automobile factory, even if the shiny Mercedes sedans and Porsche sports cars it rolls out are bound for mantlepieces, not autobahns. You see, this factory makes German model cars.

Still, giving visitors a tour is virtually impossible, says Britta Sieper, 35, who heads the company in Lüdenscheid, Germany, that makes the Siku and Wiking brands. "Because of the contracts we sign with car manufacturers to keep all details about new cars secret, it’s more difficult than it used to be."

The manufacturers expect that details about what their new models look like will not leak out, as the Sieper Group makes the miniature versions that will become available when the real cars do, as gifts or collector items.

Until recently, for example, nobody knew what the VW Golf VII looked like, except its manufacturer and the folks in the Sieper company’s German headquarters. The idea that somebody could sneak in and take a photograph of a new model is unthinkable.

But now, anyone wishing to know how the small collector items and toys are assembled -- largely by hand -- is in luck. Last year, Britta Sieper and her father Volker opened the Siku ∕∕ Wiking-Model World at the company base in Lüdenscheid in North Rhine-Westphalia where for a five-euro ticket visitors can check out 3,500 miniature cars.

The upper floor is where sturdy Siku brand toy cars are, and the ground floor is devoted to the smaller (1:87) Wiking cars, 90% of which are bought by collectors. Together, the displays represent more than 90 years of company history.

Gerhard Möhrke from Gütersloh, Germany, buys every new model car that comes out of the factory, about six per year. Prices for new models don’t tend to rise much anyway, he says, the valuable items are the old ones dating from the 1950s. Some of them can bring as much as 10,000 euros.

The Sieper Group is a fourth-generation family owned company that counts some 700 employees. Founder Richard Sieper started out making household articles out of plastic, then added toy cars to their production in 1951. The Group took over Wiking in 1984.