Sorry to dig guys, but i found some info that the SA boys might be interested in. The DTEI (department of transport, energy and infrastructure) says that for a steering wheel to be legal in SA it must be 330mL diameter or more, and needs to be ADR approved. I rang them, so dont dispute my facts.
BUT, also heard something about legalities regarding boss kits for the wheels in SA. Apparently they must be collapsable or something, but thats another story.
In short, DTEI say 330mL min and ADR approved.