The other option is DFW-NRT-HKG-KUL-land-SIN-SYD-JNB-LHR-DFW
CX definitely flies to KUL - Kuala Lumpur - from HKG. I'm not sure about driving, but with Malaysian and Singapore Air offering special 'shuttle flights' see
http://www.kiat.net/klia/airlines.html that would mean only one extra trip.
Cheers,
TravelTil