To prevent debris, oil, fuel, or coolant from falling on the racing surface, "diapers" under the engine (with a supporting platform) are used to retain liquids and broken parts in the event of a catastrophic engine failure. "Oil-downs" result in substantial fines and the loss of previously earned Championship points (for annual awards). Many cars using the centrifugally-activated "slipper" clutch are now using a retention tube to collect the substantial amount of clutch dust that is produced during each race. The afore mentioned recent practices, along with the longstanding requirement for a Kevlar-style retainer blanket over the supercharger, considerably reduce the potential for injury and fire, in addition to assuring a cleaner and safer racing surface, resulting in a dramatic reduction in race delays for track clean-up.