Who is the mother-in-law in the NAPA autoparts commercials?

In the NAPA Auto Parts commercials, the mother-in-law character is portrayed by actress and comedian, Mary Lynn Rajskub. She is known for her humorous interactions with her son-in-law, emphasizing the comedic tension often present in family dynamics. Rajskub's performance adds a lighthearted touch to the commercials, making them memorable for viewers.