The Bogan loves its car, and the Bogan loves putting bumper stickers on its car. A sentiment that has been distilled into a few short words appeals to the Bogan’s belief that the universal order is fundamentally simple to grasp, which is convenient since its past experiences of thinking about things too hard have proven frustrating and ultimately unrewarding. Perhaps this explains why the Bogan can sustain the conviction that Australia’s landmass of 7,617,930 square kilometres cannot physically accommodate any more than its current population of just over 22 million people.
This idea is perplexing, but the Bogan appears to believe it firmly enough to plaster it on the back of its beloved car. Believing Australia is fatally overcrowded, one does wonder why the Bogan pumped out three kids in the last two and half years, and this is yet another example of the kind of fascinating contradictions constantly thrown up by the phenomenon of Boganism.
At the risk of doing TBL readers’ work for them, the sticker makes a lot more sense when you look at it this way: Australia is not ‘full’ as far as the Bogan’s own kind is concerned – the message is intended for foreign immigrants, particularly asylum seekers. The Bogan is not racist, but believes that immigrants (only the brown ones, of course,) don’t ‘assimilate’, by which it means they don’t become Bogans. Naturally, the Bogan has never actually met a refugee before, and bases this opinion solely on something Aaron was saying in between mouthfuls of beef and black bean the other night. One of the most illustrative insights into the Bogan’s confounding pathology is that the Bogan claims to like each and every brown person it has ever chanced to meet, yet continues to maintain the opinion that every single other brown person is some kind of hybrid of Osama Bin Laden and Idi Amin.
To its marginal credit, and despite the fact that the Bogan drives about with a racist statement on the back of its car, a true Bogan is unlikely to be a member of an active white supremacist hate group. That would mean straying too far outside of the warm, cradling mainstream, and besides, their meetings clash with Two And a Half Men. Also to its credit is the accurate grammar and syntax of the printed sentiment.
No, the “Fuck Off, We’re Full” sticker is racism-as-automotive-adornment, a nod and a wink to other racist Bogans – “yes, I’m a racist too, it’s OK, you belong. Now please admire my sick rims”.
*UPDATE*
There have been some expressions of doubt that these exist. Doubt no longer.
This form of disclaimer can be extended beyond occasional interactions with foreigners, and many bogans will actively carry, wear or enact visible or tangible evidence of their god-given right to besmirch those who differ from them. Common examples include 
What’s a Catchier Phrase than ‘Recent Comments’?