Agree with anthomson - I reckon you're thinking of River City People. Liverpudlian band, female singer who went on to present the Clothes Show for the Beeb.
i have to agree with docscott. the beach boys did indeed cover california dreamin' in the 80s. it was a really bad version with loads of overlaid guitars and vocals. i remember it because my housemate at university used to annoy me by playing it all the time.
All these Artists have covered the song:
California Dreamin' covered by REM
California Dreamin' covered by Beach Boys
California Dreamin' covered by River City People
California Dreamin' covered by Four Tops
California Dreamin' covered by Henry Kaiser
California Dreamin' covered by Crowded House
California Dreamin' covered by Guster
California Dreamin' covered by Dada
California Dreamin' covered by Elk City
California Dreamin' covered by Jack Frost
California Dreamin' covered by Bobby Womack
California Dreamin' covered by Ventures
California Dreamin' covered by Melanie
California Dreamin' covered by Seekers
California Dreamin' covered by Los anillos de bronce
California Dreamin' covered by Pennywise
California Dreaming covered by Motorpsycho
California Dreaming covered by Hi-Standard
California Dreaming covered by American Music Club
California Dreaming covered by Jose Feliciano
California Dreaming covered by Killing Miranda
California Dreaming covered by Goteki
California Dreaming covered by Dead Artist Syndrome
California Dreaming covered by Fleming & John
California Dreaming covered by DJ Sammy
California Dreaming covered by Guster
California Dreaming covered by Paisley Wheelchair Experience
so many bloody covers!!! I was hoping one of you could tell me which one was used recently as the final song on an american movie? Slow bluesy version with janis joplin esque singer and guitar. That's it though, I can't remember the name of the film... Good luck...