So it was the confederate flag that tipped the scales?

Because we know that the "88" (for HH -Heil Hitler) Wouldn't antagonize ant muslems.
Hitler is as popular to them as Che is to the staff in the White House.

Lets decipher the rest of that coded message...

The number 88 stands for the eighth letter of the alphabet, H, doubled to signify "Heil Hitler," said CAIR's Ibrahim Hooper. "CV" stands for "Confederate veteran" -- the plate was a special model embossed with a Confederate flag, which Virginia makes available for a $10 fee to card-carrying members of the Sons of Confederate Veterans. And 14 is code for imprisoned white supremacist David Lane's 14-word motto: "We must secure the existence of our people and a future for white children."

OR- could it be that they were offended (again) by the graphic on his tailgate?

The giveaway that something was amiss, Hooper said, was the truck itself. An enormous photo of the burning World Trade Center towers covers the entire tailgate, with the words: "Everything I ever needed to know about Islam I learned on 9/11."

The way everyone is going out of their way to get offended, pretty soon they'll have to issue blank plates.