F1 Budget Cap: Impossible to Enforce
And even if (IF) this system worked how can this be explained to the fans succinctly, and why should they care? It has little to do with racing other than holding out the potential to mar the credibility of a championship as we're seeing with the rumors that are going around about the Red Bull team's spending in 2010.
Furthermore, suppose the team was found to have exceeded the cap. Then what? Strip them and their driver of the titles? That would be a PR disaster. The problem with racing rulemakers is too often they come up with rules that are not practical to enforce. Sure, it would be great if no team spent more than the cap. But proving or disproving that is so far removed from the realm of what the fans care about that it's academic.
I've said it time and again: Racing results should be decided definitively at the moment the checkered flag is waved. There should never be any doubt of the race result right then. And should there be an exception (scrutineering, driver penalties, etc) it should be decided quickly after the event. It should never drag on into another day.