This thread may have something to do with the "skittle?" thread, but in "The Fast And The Furious", when Brian Spillner (aka Paul Walker) is revving up his green Mitsubishi Eclipse at the stadium (just after the first truck hijacking), what is the weird noise that the engine makes as it revs back down? It's a sort of cross between humming and buzzing... hard to put my finger on, but is really obvious. Look at the 2nd chapter on the DVD.