KEPT BUSYA driver is distracted (or kept busy) by another driver who is relentlessly pursuing.
KEVLARA brand name for a certain type of carbon fiber, used in everything from driver's helmets to bodywork to bulletproof vests used by police. A very strong, expensive and lightweight material.
KICK A LEG OUT OF BEDAn engine breaks a connecting rod, which penetrates the engine block and ends a driver's day. Announcers describe this as the engine "blowing up."
KITTY LITTERThis term describes two things: the absorbent powder used to soak up fluid spills on the track (often real kitty litter) and the gravel runoff areas on the outside of many road course turns that help slow cars that go off the track.