You have to remember that anyone owning a car in Singapore is loaded. This due to the fact that there is no space and the consequent laws to turn off anyone owning one.
e.g. super expensive car parks, even to park on the street. High anual cost, toll, petrol prices and so on.
They even check your tank when driving back in to Singapore from Malaysia, If it is above certain level there is a fine or tax I believe.
On the other hand it is a marvelous place where the public transport is so that you don't need a car. (and the food is great too!)