IN THEIR second collaboration (after "My Beautiful Laundrette"), writer Hanif Kureishi and director Stephen Frears once again take to London's disaffected streets. And if "Laundrette" seemed convoluted and pointless to you, then "Sammy and Rosie Get Laid" will quadruple that measure. In this mania of political themes and sexual farce, "Laundrette" would amount to a minor sideplot.

Sammy and Rosie, Boho Yups, are part of London's rainbow coalition of Pakistani, Indian, West Indian and African immigrants. Sammy (Ayub Khan Din) loves his girlfriend but is seeing an American photographer. Rosie (Frances Barber) doesn't love him nearly so much and is seeing a squatter called Danny (Roland Gift, lead singer of the Fine Young Cannibals rock band). Sammy's father Rafi (Shashi Kapoor), a socialist turned fascist from Pakistan, returns to London to assess the political situation. There's also a Romantic Englishwoman (Claire Bloom) he once had the pleasure with. Rosie employs two lesbian radicals to bring her up to date politically. They get on Rafi's case. Oh, and Margaret Thatcher's London is burning with race riots.

The trouble is, since few characters are fully developed, it's hard to care who's doing what to whom and why. Ayub Khan Din has an endearing desire to please, and Claire Bloom injects sweetness into her mini role. Kapoor puts moments of honesty into the self-important reactionary Rafi. But there's no time for empathy -- what with all the plots crowding each other and Kureishi's urgent statements and pressing witticisms. Frears cuts madly about to cover everything. The fevered pace reaches its zenith when the screen splits three ways to show three couples doing what the movie's subtle title says.

Kureishi's diary, accompanying copies of the script, mentions his desire to fill "Sammy" with "realism and surrealism, seriousness and comedy, art and gratuitous sex." The studied flippancy of the remark is appropriate. "Sammy's" Boho-blase' mood makes you watch dispassionately. You're never drawn in because Kureishi and Frears seem more interested in viewer assault than anything else. Your first impulse, as when angry demonstrators of Brixton start hurling things, is to duck.

SAMMY AND ROSIE GET LAID (Unrated) -- At area theaters.