Join Date: Jul 2004
Location: Live: IWI; Work: DCA/Everywhere; Play: LAS/SJU/MLE
Programs: AA EXP, DL PM, Hyatt Glob, Marriott Ambassador/LTP, Nat'l Exec Elite, LEYE Gold
Posts: 7,440
I would use BA.com instead of CX's website. Make sure to check one segment at a time, LAX-HKG then HKG-SGN etc.
Also consider flying Japan Airlines through Tokyo to SGN. Japan tends to have decent availability out of SFO so check that too (you can add on LAX-SFO on AA). Indeed, I just happened to randomly check April 16, and there is business class availability on JAL for SFO-HND-SGN.