Auburn could claim AP national champs of 04 all they want had they been credited so. But, they weren't. So they can't claim that.
If they were named National Champs by the AP, though, I'd have no problem with it at all because unlike you LSU fans, I'm not bitter about my team being overshadowed by another, and I hate the BCS and anything that causes controversy in college football and criticism towards the BCS is great in my mind.
Plus, we all know USC would have killed Auburn that year anyway. That's why nobody really brings it up or even tries to argue that Auburn should have been named AP national champs. Even despite the eastcoast/SEC bias, USC was still named National Champs by the AP in 03 because they were that good and everybody knows it.
Don't hate the player hate the game yo.