When Bobby introduces Jimmy Carter to Hank and Peggy, the windows of the limousine are down, showing people in the front seats. On the exact frame that Bobby closes the door shut, the car makes a several visual changes, most notably: all the windows are suddenly up, and the people in the front seats are no longer visible. This happens around 16:33.
Hank says they will start a new tradition, "Christmas with the Niefkos." Niefko is the guys first name. What Hank should have said was "Christmas with the Lubeckis. Lubecki is the family's last name.
Buck Strickland says Hank has been with him through two wives but Buck has only ever been married to Miss Liz.