So what if the guy has a bunch of "Obama sucks" bumper stickers on it?
Would they have told him not to park in the FD lot if he had "Bush sucks" stickers on it?
I say it's just another case of politically correct people going too far and overstepping the boundaries of what they can do in terms of the workplace, which, in this case, is unnecessary censorship.
If a firefighter had a pro-homosexuality or pro-Islam bumper sticker on his vehicle and the FD told him not to park it at the FD for that reason, you can rest assured the ACLU would come to that firefighter's aid, and that the FD bigwigs would be tarred and feathered as "homophobic bigots" or "Islamophobic bigots".
In other words, the First Amendment apparently only applies as far as Left-wing bigots allow it to. If Leftists don't like a particular message, they'll disallow it with extreme prejudice.
Well, I guess this FD's bigwigs are pro-Obama bigots!