They're small, but some say Car2Go Smart Cars take up prime parking spots, and the Seattle City Council voted unanimously to expand the program Monday.

 There are currently 330 Car2Go Smart Cars around Seattle.

 Members sign up and pay by the minute to take the car wherever they need within certain parts the city and then park it for the next person to use.

 Since January, the service has really taken off, and the City Council has approved a plan to issue the Car2Go company another 150 permits, so as many as 500 of the cars could be moving around town.

 The service will expand to parts of West Seattle, Beacon Hill, Columbia City and Georgetown.

 Since the company brought the service to Seattle, more than 18,000 people have signed up.

 It's become a popular alternative to public transportation because drivers don't have to pay for parking.

 It's included in the .38 cents per minute fare, and the company pre-pays the city more than $1,300 per car for parking.

 The gripe for some is that the cars are taking parking spots away from other drivers and the cars can legally sit in the spots for several days before someone moves them.