originated at the focaljet by MxRacerCam. in reference to the BBC car show Top Gear and it's disdain for the C6 model chevrolet corvette's leaf-spring suspension, despite the fact that the C6 is one of the best handling cars they have ever tested.
now used in reference to any situation (and most often a thread in a forum) that is weak or without merit.
"this thread needs more leafspring"
"steeda's mom needs more leafspring"