Taxis are plentiful in Singapore. For S$20 you can get a ride half way across the country (literally).
Unless you are planning on commuting to home and back for every lunch and coffee break, taking taxis would be far cheaper than operating your own vehicle.
And you'll save time getting dropped off at your destination rather than searching for a parking space.
The parking itself will probably cost more than what a taxi would have charged for the ride. Depending upon location parking can be two to four dollars an hour.
Unless you need to drive around a lot more than most people do, the main reason for a car in Singapore is status.