TOKYO -- A brilliant Saturday afternoon sun is beaming through the picture windows and glistening off the stainless steel pillars of the Chrysler dealership on Tokyo's chic West Gaien Avenue. But inside, there's not a customer or a salesperson to be found.

That's just fine with Teruhiko Endo, the 53-year-old manager who supervises a six-member sales force. "To build a showroom and just wait for customers to come in -- that's not how we do things in Japan," he explained. "Our salespeople are where they ought to be -- out in the neighborhoods, tracking down customers."

The notion of selling automobiles door-to-door may seem unusual to the marketing folks back in Detroit, but it is one of the techniques U.S. automakers and car dealers are being forced to learn as they reach for a foothold in Japan, the world's second-largest auto market.

For years, Detroit automakers tried to impose American car-selling methods on Japan. They battled -- in vain, as it turned out -- to convince salesmen to work on a commission basis. They spent large sums on fancy showrooms even though most Japanese car salesmen go to the buyer rather than vice-versa.

Chrysler Corp.'s lavish new showroom here is just a place to stop in now and then for the salesmen. They spend their days driving spanking-clean new cars to the homes of potential customers -- mainly, people who have called Chrysler's "0120" phone number (the equivalent of an 800 number in the United States) in response to an ad.

"They call up and ask us to send a catalogue," said salesman Toshiyuki Kase. "But I would never just mail it. I drive over to the home in a {Chrysler} New Yorker or a {Jeep} Cherokee. Of course I'm just delivering the catalogue, but most of the time, I can get guy to take a test drive with me on the first visit."

Kase, 27, said his job is tougher because many residents of the high-income neighborhoods near the showroom have been visited for years by salesmen for other foreign cars.

In addition, Chrysler Chairman Lee Iacocca -- known here as "Ia-san" -- has angered some potential buyers with his strong attacks on Japanese business practices. Kase said Iacocca can also be an asset, though, because his celebrity may enhance Chrysler's status here.

Despite the late start and the Iacocca issue, Chrysler is beginning to sell cars here -- particularly Jeeps, which fit the current fad for four-wheel-drive vehicles. But the numbers are still small.

Chrysler executives here say sales this year should double 1989 figures. That would mean total Japanese sales of about 2,000 cars.