Hello once again!
A late reply is definately better than no replies so no
worries!
As per my understanding, EU cars are RHD, otherwise known as
EU-Spec, and US and a FEW other countries are LHD, otherwise
labelled US-Spec. What we get in Singapore are EU-Spec M3s.
And about RHD not being produced in large numbers, pardon me but
IIRC, RHD make up > 65% of BMW cars produced. Only the US, a
couple of Asian countries use LHD cars.
CS option (ZCP in the states, M-Competition package here) i believe
uses the same assembly line because the suspension is now put on
ALL M3s and the only difference is the M-Track mode and the CSL
rims with a few other minor changes.
Here's a little known fact for people that assume SA produced cars
are of "lower quality". BMW-es produced in Europe receives the MOST
complain about quality, all other parts of the world second, and
surprising here, SA receives the LEAST complains about build
quality. So undoubtedly, SA is definately not lacking in the QC
aspect.
Cheers!