According to NPR there is a lot more to this story.

The County went on a buying spree because they got a great deal on 908 cars. The money they saved from buying in bulk was enough to make up for storing the cars. There were 17,000 people that had cars checked out to them, so 908 was just a normal replacement volume.

Then came a major revamping of 'who gets to drive a car' rules and the country found they had a lot more cars than they needed. So they stored them.

They have also maintained them, starting and driving each car a bit every two weeks. They need to replace about nine cars a month, so with the 157 they currently have in storage they will be needing to buy more in 17.4 months.

And at least one Country Commissioner has been looking into this since about 2010, but after checking out the situation it seemed it was cheaper to keep on keeping on.

More details at NPR.org.