First Amendment: Part I "Separation of Church and State"

Congress shall make no law respecting an establishment of religion, or prohibiting the free exercise thereof; or abridging the freedom of speech, or of the press; or the right of the people peaceably to assemble, and to petition the Government for a redress of grievances.

A war is being waged through a very unlikely medium: license plates.
The Americans United for Separation of Church and State have recently sued the state of South Carolina over its potentially unconstitutional DMV-issued plates with "I Believe" accompanied by a cross. They are suing on behalf of a rabbi, two Christian pastors and a Hindu organization. As of right now, the federal courts have ruled on a temporary injunction to hault the distribution of the plates.
Now here is an interesting situation: religious organizations suing to quiet another religious group's freedom of speech. Can you say, "Shooting yourself in the foot?"
This case can be argued two ways:
1) The AUSCS can argue that the S.C. legislature is supporting a religious establishment by passing a law that creates a Christian-specific plate. On these grounds, yes, the S.C. legislature's Act No. 253 or the "I Believe" Act, is wrong. However....
2) It has been established that vanity plates fall under freedom of speech, and as such, the religious organizations suing the state are harming their own freedoms if this nonsense is passed. First, why would two Christian pastors have a problem with "I believe" being inscribed on a license plate? The followers of these Christian leaders need to seriously re-assess their ideals and those of their pastors. As for the non-Christian leaders: Why would they not push for their own religious-specific license plates in the hopes of having equal opportunity to express their ideals instead of squashing those of others. Freedom of speech means just that; freedom. It does not mean, "His speech hurts my feelings because I believe differently so it shouldn't be allowed!"
The only way that the AUSCS has a leg on which to stand is if the S.C. Legislature decides not to pass or ban license plates that say, "Allah is king." Only at this point is there a freedom of speech violation. Until then, the religious groups should put an add in their establishments' bulletins asking for lisence plate ideas.

Related links:

Ind. appeals court backs 'In God We Trust' license plates
7th Circuit: Ill. not required to issue 'Choose Life' plates
9th Circuit: Ariz. wrong to deny 'Choose Life' plates