Although research on smart cars has rapidly expanded, relatively little attention has been paid to improving users' emotional experiences. This research was based on a petmorphic design approach, which defines design attributes assuming an intelligent device can interact like a pet dog. In this paper, we present a set of pet-dog behavioral traits (PBT) and their application in enhancing emotional interaction in smart cars. Firstly, using an interview-based explorative study, we identified key pet-dog characteristics that elicit affection in owners and four PBTs that could be used to design smart car interactions: self-expression, empathy, faithfulness and innocence. Secondly, we conducted an online survey-based study to examine how PBTs can be incorporated into smart cars for different scenarios. The results indicated that faithfulness was typically preferred in routine scenarios while traits associated with innocence were less preferred. We discuss the desirable use cases for each PBT and how PBT can be applied as a function of autonomy according to the urgency of a situation. We also discuss how PBT could enhance users' emotional experiences by increasing agreeability, emotional bonding, delightfulness and generous attitudes.