Here's one of the cars missing from Nascar Racing by Papyrus. It's Nascar 
champion Dale Earnhardt's #3. Copy EARNHRDT.PCX to your nascar directory. 
I replaced car#48 by renaming EARNHRDT.PCX to PHOS48.PCX then go to the 
paintshop and select car#48 then click on import.  Then go to the other 
part of the paintshop and paint all portions of the car black. You can 
replace anyother car with Earnhardt's by first selecting it and export 
it so that you can get the filename.  Then simply rename EARNHRDT.PCX 
to the name of the car you want to replace and import it in.