My uncle thoughtfully put a bumper sticker on the bumper before I went over to get the truck:

For those of you who may not know, an arroyo is a wash, or a gully, usually in the adobe hills, that only gets periodic water running through it.  In the more redneck areas, it's where you put all the stuff that you don't want anymore--like old washing machines and broken glass.  And wrecked jeeps.

Hah hah.