Auto certification shops doing brisk business along border

Some are construction workers who can no longer find work in Las Vegas or Phoenix, where growth was rampant until the mortgage bubble burst. Others are simply fed up with having their status questioned.

In order to take a car into Mexico, you must have your name on the registration as at least part owner and if there is a lien on the vehicle, you must have a letter from the bank or other financial institution allowing you to venture across the border. You also need to insure the conveyance in that country.

A Mexican citizen would also need a clear title and current registration plus Mexican insurance, and an address in Mexico to register the vehicle in that country.

Of course, they will have everything they want to take with them. After returning home, why risk being maimed or killed in an ever more expensive and forbidding border crossing to retrieve a few more material possessions. Chances are the undocumented would return only for remaining family members.

According to Mexican census data provided to Nogales International, the primary source of the information, 351,000 Mexican nationals have returned over the last five years, one third of the 1.1 million who emigrated to the U.S. in that period.

Ten years ago, only 17 percent of those who came to the U.S. ever returned home.