Really depends.
LTA rules allowed tourists to travel in their cars and exempt from
any local requirements. The just have to pay the VEP fees.
But since he is the CFO, he should have a employment pass to stay
in singapore that means he must own a car that complies with LTA
requirements.
Unless by some way he managed to say his wife is a tourist.
Do you know back in September last year a Swiss couple driving a
1984 Toyota Landcruiser came to Singapore?
They have been driving around the world since 1984. mileage on the
car is 600,000km already.