The Calzone - S7-E20
Factual error: When Jerry gets a speeding ticket, he asks Nicki to give the officer the registration. She gets a large piece of white paper from the glove compartment. That's what car registrations look like in California, where the show was produced. In New York, where it's supposed to take place, car registrations are the size of a driver's license, and are usually kept in the driver's wallet.
Answer: The name is Delores. He shouts that name at the end of the episode. Then in a later episode, "The Foundation", he runs into her. And he repeatedly calls her Delores.