Cost of a car in SIN
I lived 3 years in SIN (flying for Tiger) and had a car. Bascially, all short haul guys have cars, because you travel to the airport every day. If you are long haul, it's maybe not worth it. Depends on you. Family might want a car.
Prices have come down considerably. If you take a modest model, you get it cheap. 3 taxi rides a day and your car costs are covered.
Advantage with a car: You can take apartments a bit off the route, so you might pay a bit less.
hth,
Dani