What is the meaning of this British idiom?

I was watching BBC's Top Gear and the presenters were cracking jokes about people who live in the 22 of the avenues. And that the people who live there like to give nicknames to their home and have specific decoration, stating that they lived in the 22 of the "Acacia Avenue".

As it is also an Iron Maiden song, and since the band is also British, what is up with this expression?

I can't recall in what Top Gear's episode that phrase popped up, but I'm sure it was around the 2008 season.

I found this wiki entry too: <http://en.wikipedia.org/wiki/Acacia_Avenue>, Which is midly informative. I see that is something linked to the middle class, but I want to know more about the nuances.