A backseat DUI occurres when a sober
person is driving an intoxicated
person home, and the intoxicated individual is giving the driver
shitty directions, and false instructions to turn, and then saying "No, No, not this street..."
This causes the driver to speed up, slow down, and begin to turn, then swerve back into the driving lane, leading others observing the vehicle from the outside to believe that the driver is DUI.
"I was driving Marcus home the other night from the
local water
hole and he kept telling me to turn and shit and I was all over the place and then I got pulled over, but it was cool, the cop realized Marcus was just backseat
DUI."