Ok, this guy is either a master of irony or a complete moron.

dry cleaning at it is best

In case you can’t make it out, the sign says, "Dry Cleaning at it is best".

Astonishing. Of course it’s the logical next step from the usual mistake of confusing the possessive its with the contraction it’s but still…

Many thanks to Claire who spotted this "somewhere in south London" although here at GrammarBlog we can’t condone photography while driving.

Hang on, we’re not the BBC. Drive and take photos as much as you want. In fact, why not have a couple of beers first?