When a slower vehicle overtakes a faster vehicle after a speed contest. After the speed contest has finished, the slower vehicle proceeds to pass the faster vehicle to inflate the ego /recieve an erection/brag to friends, or any combination of the above. This loser flyby can be performed by any make/model of vehicle, as long as the said car is significantly slower than the opponent. See also ricer flyby
, meathead flyby
Billy-boy: Did you see that joe-bob, I just smoked that riceboy civic there?
Joe-bob: No you did'nt, you just performed a loser flyby.
Riceboy: Bro I just dusted that Mustang...
Riceboy's friend: Dude...that was a total loser flyby.