Jaclyn Trop:

When Lindsay Frandsen thought about registering for gifts for her wedding, she realized that what she and her husband really needed was a car.
 Ms. Frandsen and her husband, Christian Burris, opened an account with a start-up company that lets potential car buyers reach out to their social networks for gifts.
 One year later, the couple had scraped together a down payment from their savings and the gifts from the registry. Hyundai also gave them a $500 credit for taking part in the program.
 “We got a good chunk toward our down payment,” Ms. Frandsen, a 26-year-old driving instructor from Atlanta, said without being specific. “It’s like 500 free dollars, basically.”