WEST HOLLYWOOD, Calif. — A clutch of stylish-looking women are gathered around a sleek SUV that has pulled up to the curb on a trendy avenue.

Just another location shoot in La-La Land; nothing too unusual about that. So why does a woman passer-by suddenly scream with joy and tear across the street to get a closer look?

Because she's just realized the femme bunch is the cast of "The L Word," which usually doesn't film in Los Angeles.

Showtime's series about a diverse group of L.A. lesbians shoots mainly on soundstages and locations in Vancouver, British Columbia. But how many palm trees can one show fake? So production for the series' fourth season, which debuts Sunday, moved to Southern California for several days of shooting at places where the characters live, love, work and play.

Series co-creator Ilene Chaiken hesitates to dub Los Angeles a "character in the story." There are, after all, at least 12 main women characters whose stories she's got to fit into this season's dozen episodes.

But she acknowledges that "the cultural dynamics of L.A. are embedded in our show. The characters do have L.A. values and are affected by L.A. values to some extent, so I think the series has the specificity of a unique culture and environment but it is dominated by universal emotional experiences that everybody can relate to."

Among the series' leading women are Jennifer Beals as Bette Porter, Laurel Holloman as Tina Kennard, Leisha Hailey as Alice Pieszecki and Daniela Sea as Max Sweeney.

Newcomers this season include Cybill Shepherd as Bette's boss, Phyllis, who comes out later in life after a heterosexual marriage; Marlee Matlin as Jodi, a deaf artist who has a relationship with Bette, and Rose Rollins as Tasha, who has served a tour of duty in Iraq.

Serious issues — such as the military's "don't ask, don't tell" policy, the legality of same-sex marriages and the challenges of transgender transition — underscore story lines, but "Sex and the City" style wit and laughter also hold sway.

"In the sense that we deal with the issues of the moment, we deal with them because they affect all of our lives," says Chaiken, who doesn't presume that her show will necessarily change people's attitudes but does hope that depicting lesbian stories in all their human variety may shift opinion.

Chaiken notes that her aim this year was to "slightly notch up the melodrama while trying to keep it real ... and to keep the humor, not get too dark, too heavy." She wants the series to show "happy lesbians" at least a good portion of the time.

"Every time I go back to it, I treat it as if I'm doing a new show ... we really do try to shake it up ... and I think that it's much more true to life in that this is a show about a group of friends, and one's friends change all the time, romances change, and where people are in their lives changes," she explains.

To help sort out who has loved or does love whom, the plot line has always included Alice Pieszecki's wall chart, which chronicles all the romantic hookups. This season, the chart goes online and interactive.

That concept also has moved from fiction to reality, as Chaiken has just announced the formation of a company, OurChart.com. It's an online social space for lesbians and their friends. Beals, Moennig and Hailey are among the founding partners.