The Westin - Crystal City parking/airport shuttle deal was very reasonably priced and easy to use. Using Book2park.com, I reserved a parking spot at the Westin, which is in a secured underground parking garage at the hotel. They provided very detailed instructions and payment information for the drop off and return of my car, and the shuttle info. The shuttles are roomy and the drivers are friendly and helpful with bags and airport departure info. It was nice sitting back and letting them take care of knowing where to go. Would absolutely use again when flying out of Reagan airport - DCA.