There are restrictions that dictate whether a car dealership can operate on Sunday. The few dealerships that are open on Sunday are open because of the competition.
Weekend sales are hard due to banking institutions being closed, which is one of the main reasons most dealerships do not operate on Sunday. There are also 18 states in America that legally restrict dealerships from operating on Sunday, while eight other states have a mixture of laws saying whether they can. The rest of the states are free to conduct business on the weekends, but tend to avoid doing so unless necessary, according to AutoNews.