The reason some race cars need a diaper is because of the rules is a band aid for the real problem of oil down cleanup which should be the responsibility of the race track in my opinion .
The tracks are too cheap to buy a machine to clean up the oil downs
http://www.waynesindustrial.com/trackscrubber.html
this is one example of the machines ready to be used at a track. I have been at a lot of race tracks and they are still using the same brooms and butane torches that they used 25 years ago . Shame on them All the up dated rules have been made for the racers yet the tracks are still cleaning up their tracks the same way they did 25 or more years ago and I swear with the same tools . Every race track that runs under the NHRA banner should be required to have one of two power machines to clean up any oil downs this would make racing a lot quicker with the very simple solution buy the machines LOL
Now after saying that I would put one on my car maybe if it would fit but I don't think it would fit as my car sits very low in a 2005 Sun fire with a 455 SD Pontiac engine with headers right where any diaper would have to be bolted on . now if the diaper maker wants to make one and then fit it come on down . Remember my pan is very low so the diaper will have to be not hanging down at all