In Dayton, the rifle user was confined in a bar, not in a moving vehicle and the backstop was the wall of the building.
And, just to be clear, the Dayton shooter was firing what is legally classified as a pistol, although most people would consider an AR-15 with a shorter barrel more akin to a rifle in a firefight than, for example, a 9mm pistol.
Hitting anyone in a moving vehicle is hard unless you are also in a moving vehicle, but since apparently the shooter in Texas was also the driver it doesn't seem that he had much of an advantage since he was shooting one handed while driving.