I DO beleive that some "phantom cautions" have been thrown from time to time, but to the level of unfair competition I'm not going to be jumping on board. You're only ever going to find solid proof of "phantom cautions". Unfair competition wouldn't fly due to people like Stewart who are pretty liberal with their words. The idea that engines were rigged to blow goes as far back as the All-Star race that DW blew the engine just after the finish. If they were rigged you wouldn't see a boring finish (completely boring anyways) ever. Plus, I've always said. You can't rig something when you're going that fast, that close together, and that close to the edge.
You could say the same about te Rolex Sports Car Series or F1, or look at the Indy 500 this year.. how's come the same people win all of the time in F1 and Rolex Sports Car Series? It's because they have better equipment and have figured out the track. It's just not logical to rig a race from this point of view besides throwing yellow flags when they shouldn't be, and there was a phase around '06 where that seemed to happen alot, but I havn't even seen much of that recently.
Myself, I think they should run until there's 2 to go and then throw a competition caution just to make sure that the fans get a show. I mean, the people payed good money, so why should they have to watch a boring race? lol, at least they havn't done this.