Car for sale?

You all know I love my car. I've had the Prius for less than a year-and-a-half, and, well, I just love it. But you also all know that I bought this car when I still lived in Salt Lake City and didn't know I would be leaving. Didn't know I would be moving to a city in which I very rarely actually need a car. And now I'm wondering if I ought to do something very scary: sell my car.

It's been very nice having my car while I've lived here. I've only used it about once every two weeks, but when I've used it, I've been glad to have it. Without it, I couldn't have taken all those trips to Richmond to visit relatives. I couldn't have taken Edison to the vet in Maryland - or anywhere, really, since you can't take dogs on the Metro or buses. I couldn't have picked visitors up from the airport or made big grocery shopping trips where I bought too much stuff to walk home or gone to Ikea to buy a new coffee table.

Well, actually, I could have, with Zipcar.

Zipcar is a service that lets its members use one of their cars when they need them, without having to pay for insurance or a monthly car payment or registration at the DMV. There are different plans, etc., but basically, the one I am considering comes with a $50/month payment, which goes toward your car use. So I am committed to using the car at least $50 worth, and when I use it more than that, I pay $8.10 an hour or $60.30 for a 24-hour period. The best thing is that that price includes insurance and gas! So even with heavy use, I couldn't see myself spending more than $200 a month on driving, rather than the more than $550 I currently pay for my car payment and insurance, plus gas. And Zipcars have reserved parking spots - a huge plus in a city where it sometimes takes a half-hour or longer to find a parking spot in your own neighborhood. And yep, pets are allowed in Zipcars.

Bonus: Blue Book tells me that my car right now is worth about $4,000 more than I owe on it! The beauty of owning a car that is in super-high demand!

But this is a hard decision for me to make. I have lived without a car before - in Logan, Utah, no less, where there is not quite the level of public transit available that we have in D.C. Still, it's nice knowing that I have a car right there when I need it. (Of course, the concept with Zipcar is that you still have a car right there when you need it. There are Zipcar locations all over this city, some closer to my house than some of the parking spots I end up with now.)

So I need your help. This is one of those decisions I need people's input on. Is this a terrible idea, or a brilliant one? Can anyone think of any possible problems this would cause that I've overlooked, or any other benefits that I hadn't thought of?