Wednesday night, I needed to get from Georgetown to Nationals Park. I hadn’t driven there, and a bus-to-train commute would have taken 45 minutes. Instead I jumped into a Smart Fortwo I’d never seen before, scooted across the district in less than 20 minutes, and ditched the car in a metered space two blocks from the ballpark, without paying.

No car theft or parking tickets were involved. Instead, I used a new car-sharing service called car2go that employs a fleet of GPS-linked, 3G-connected vehicles to allow instant, point-to-point rentals. It’s an interesting case study in what’s possible when a car knows where it is and can share its location with a network of users.

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Car2go, a subsidiary of Daimler AG, debuted in Austin in 2009 after a test launch in Ulm, Germany, the year before. Weeks after I was introduced to car2go during the South by Southwest conference, the service arrived in the nation’s capital and has since come to Portland, Ore. It departs from earlier car-sharing options like Zipcar in three ways: You don’t need to reserve a block of time, you can take a one-way trip, and you can park in almost any legal spot on the street.

Car2go paid the city $578,000 for a year of that privilege, District Department of Transportation program manager Josh Moskowitz wrote.

After registering online — my RFID-chipped membership card showed up six days after I applied — you rent a car by booking it through car2go’s site, iOS app or third-party phone programs. Or you can walk up to one, tap your card on the sensor in its windshield, and wait about 30 seconds for it to confirm the reservation. Tap your PIN on the screen in the dashboard, and you’re off.

Rentals cost 38 cents a minute up to a $13.99 hourly rate, which then switches to a $72.99 daily rate if you drive long enough. A prepaid gas card in the glove box covers refueling.

It helps if there’s a car near you. Spokeswoman Katie Stafford says the service lets cars wind up where they may, only moving one if it goes unrented for too long. So far, the densest concentrations have been just outside of downtown.

You also have to end a rental in your “home area”; here, it stops at the district’s boundaries and excludes places like Rock Creek Park and the Mall. Another catch is insurance. Although car2go’s legalese doesn’t spell it out, you’re exposed to $1,000 deductibles for damage to the car and for third-party liability. So drive carefully, as if you’re borrowing somebody else’s car.

The two-seat Smart is a quirky vehicle. It’s laughably easy to park something 8.8 feet long, but its semi-automatic transmission sent the car bucking through shifts in its automatic mode. The clutchless manual mode (which won’t let you redline or stall) allowed for a smoother ride, but rowing my own gears without a tachometer was a little nostalgia trip.

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Car2go’s touch screen includes a basic navigation function. It didn’t let me search for destinations and didn’t factor in traffic, resulting in a prolonged crawl from Capitol Hill to Dupont Circle on a second rental. An “Apps” button does nothing today, but Stafford said it will eventually bring up tools like the “Eco Score App,” which lets renters in Berlin check their driving efficiency.

Is car2go worth it? My first run over to the ballpark only cost $10, while a taxi would have cost $16 before a tip. But the second would have been faster and cheaper on Metro, even if the subway wouldn’t have allowed the gleeful experience of parking for free.

Credit: Rob Pegoraro / Discovery