I had several cars while living in Taiwan. I had the last car (a 1998 Toyota Tercel) for 2 years and put a total of 8,000 km on it–mostly when I used it to commute from a suburb to my office in Tapei. This only worked because I had free parking at both places (a very unusual luxury in Taipei) and I was able to take uncongested roads most of the way (also very unusual). When we moved downtown I stopped using the car almost completely. We sold it when it was exactly 2 years old for NT$280,000–just over half what we paid for it.
If you have free parking at your apartment, it’s nice to have a car. If not, it’s probably more trouble than it’s worth. At the last apartment we lived in, I often had to cruise the neighborhood for 30-45 minutes to find a parking space. It was so bad that we often just took a taxi instead. Taxis are relatively inexpensive in Taiwan. Also, if you park on the street your car WILL get damaged. People think nothing about using your bumper to let them know when to stop backing up.
Another issue is taxes and insurance on the car. We paid about NT$20,000 a year for insurance, and about NT$15,000 or so in taxes. Unless you head out to the country pretty often, it could be more economical to just rent a car when you need one. I’m not sure what rentals cost these days. Gas is also more expensive than in the US.
My favorite form of transportation in Taipei was a scooter. These could cost from NT$10,000 to NT$80,000, depending on the quality and wheteher its new or used. Most are between 50 and 150 cc.The advantages of scooting in Taipei is that parking is much easier and you can weave in and out of traffic to a certain extent–so it’s a lot faster than driving. The disadvantages are that scooters don’t have the same rights are cars, Taipei gets an awful lot of rain, and you will sweat a lot in the summer.
Hope this helps.