First of all, let's NOT call it California Express :P
I know that Chungking Express had a historical pun, subtly referred to Hongkong reunification with China. Let's put that aside for a while and assume that this can be brought to 2010 and fully Americanized, or... Hollywoodized.
And I know that even a director of Michael Haneke calibre remade his own movie in Hollywood. Just pretend that... it didn't happen.
My first choice would be, of course, Quentin Tarantino. He, afterall, endorsed this movie to American audience way back when. The layered story is just his style. More action. More sarcastic comedy. More witty one-liners. High BDQ.
Cop 223 would be played by: Umm... I don't know. Ethan Hawke keep popping into my head. Could it be...?
Instead of California Dreamin': Sliver (Nirvana)
Next, Alejandro Gonzáles Iñárritu. Perhaps, a little bit more poignant. Everyone will have their story told.
Cop 223 would be played by: Gael García Bernal
Instead of California Dreamin': The End Is The Beginning Is The End (Smashing Pumpkins)
Last, Danny Boyle. One word: Trainspotting.
Cop 223 would be played by: Ewan McGregor
Instead of California Dreamin': Song 2 (Blur)
Now... it's been quite a while since my last chungking jog :-?