Gilt City is offering $40 credit towards Uber car services for $20 for a limited time. Valid for new Uber clients only. Limit of one voucher per member. Offer must be redeemed by December 19, 2011.

Uber is cars service platform that matches customers with pre-approved drivers via their iPhone app, Android app, or through text message. Uber is currently only available in San Francisco and New York City.

Here’s how Uber works:

• Request a car: text message your address or use the app to set your pickup location on the map
• Uber will send the nearest driver to pick you up and will text you an estimated arrival time
• Watch the car approaching you on the app. Cars will usually arrive within 5-10 minutes
• Your licensed professional driver will park curbside in a sleek black car. Uber will text you again when the car arrives
• Hop in the car, tell the driver your destination and you’ll be on your way
• When the ride is over Uber will automatically charge your credit card. No cash or tip is necessary. Please thank your driver but remember that tip is already included in your fare