How dirty is LA?

I finally changed the air filter in my car today (I bought the filter, I don't know, at least several months ago? But it kept being ignored in the trunk). The old one I took out was *disgusting*... Literally, as I was pulling it out, dirt from its bottom was dropping like rain. Very dry, sand-like.

I was wondering at that moment when was the last time I changed the air filter, and I simply didn't recall. And I just kept trying to remember as I walked back from the hood to the trunk.

What's funny is that when I went to the trunk to put the tool kit back I found a recept that almost turned yellow, half buried under the carpet on the far side of the trunk, and it was by chance the exact receipt for the old air filter! Dated back to January 2005 though, meaning it had already been used there for about 2 years. Ew... I had been lazy.

And, nothing feels better than warm soap water to clean my hands after that. :)