The Great Gatsby, right side up

Could you please tell me the meaning of "right side up" in the following excerpt of The Great Gatsby, chapter 3?

But as I walked down the steps I saw that the evening was not quite over. Fifty feet from the door a dozen headlights illuminated a bizarre and tumultuous scene. In the ditch beside the road, right side up but violently shorn of one wheel, rested a new coupé which had left Gatsby’s drive not two minutes before. The sharp jut of a wall accounted for the detachment of the wheel which was now getting considerable attention from half a dozen curious chauffeurs.

Thank you.