The article discusses 5 common mistakes that car dealers make when posting on Facebook. They are: 1) Posts that are too wordy, exceeding 250 characters; 2) Lack of consistency in posting; 3) Irrelevant content that does not engage the local community; 4) Lack of valuable content such as maintenance tips; 5) No calls for interaction or ways for users to engage with the content. The article provides tips on how to improve Facebook presence, such as keeping posts short, posting regularly at peak times, including local community content, and providing value to users.