That link had something about the 917 Pink Pig I posted here earlier...
"All the departments in Porsche were going to run a 917 in the 1971 race and a late budgetary issue meant that one of the two lost out... the loser got to choose the colour scheme and had their revenge. The livery was designed by one of the teams. Legend has it, sponsor Martini, were not impressed and their logo didn't appear on the car."
Ahh... Im guessing they use that iluminescent vinyl. I noticed corvette was using it for their Number plates for a while and I was wondering when someone would try using it for more graphics. The idea is nice, execution is 'not so good'.