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.
Done by a ricer/meat head after losing a race. It's the racing equivalent of a sucker punch. It goes like this: the race is over and the winning car is slowing down but the losing car just keeps going and flies by at (what seems to them, at least, to be) a great rate of speed. The losing car will most likely resemble the sound of an amtrak train (meat head) or a weed wacker (ricer).
Term given to american muscle car owners who believe that their car is something special when they race and beat a car that comes with 1/3 the horsepower. The american car is often primer and has huge meaty tires on the rear (hence the term) and pizza cutters in the front. Not made for turning, the meat head car is fast in a straight line and on motorways without turns. The meat head car also sounds like an amtrak train or a tug boat.
Mullet-sporting-redneck: Check it out Joebob, I just smoked that ricer in my hemi-cuda.
Import driver: Wow....what a meat head.