How many cars do you have in your household? Are any of them sitting there unused? If you’re a three car family and have two drivers, there is usually one car sitting idle. You probably only need a half a car or a fourth of a car, though. That’s why car-sharing programs have become so popular, especially in big cities. You pay a monthly membership fee and you can get a car whenever you want it. The cars are strategically placed around the city, and the companies are usually in cities where people often don’t use cars. Zipcar is one of these companies. It’s been around for several years with operations in New York, Boston and San Francisco among others. But the company is branching out to car-dependent cities as well, such as Chapel Hill, Atlanta and Dallas. Cars cost so much money to maintain and insure these days that it could really be a logical concept. So, how much do these services cost? The average person spends about $70 a month on their “part-time” car. That’s compared to $500 a month for your own car.